instruction stringlengths 24 29.9k |
|---|
Consider a generic up-to-date Linux distro hosting a web server. I need three humans to occasionally SSH into the same user account to perform some action that can only be done by that particular user account.
The 'easy way' to do this would be to simply allow SSH by password and to give the username/password combo to ... |
What SSL options should be avoided, due to recently discovered weaknesses? This might include symmetric algorithms, or MAC functions.
|
I have a question about SHA256. I know that this algorithm was used to encrypt a text, which I have. I also have the encrypted version of this text. My question is, can I somehow get to the encryption key with those infos?
|
I've recently read here an answer from a user about the way he hacked a server in a CTF contest. At some point in the description, he said that he did sudo vim and then spawned a shell via VIM using the password he captured before (i'm supposing he did :!bash in vim).
I'm a bit confused why he used this specific vector... |
Can someone help me what is a challenge in authentication wordbook?
|
I'm trying to understand the use of GUID and what has always left me wondering is what's so special about them that I should consider using them instead of rolling my own type of unique ID. In other words, why can't I use a Whirlpool hash like:
4bec4b25ff46e09f7d7adb5b4e6842f871d7e9670506d1a65af501cf96ddf194d0132b85e6... |
Does a Virtual Private Network (VPN) provide an encrypted connection from outside networks or from ISPs to the internal network?
|
Our server has recently become a target of what appears to be a botnet attack. The first indication was an insane amount of traffic to one of our client's websites - so heavy that the server entirely stopped responding. I believe we had somewhere near 200 queued requests on the server when I checked on it.
I've concl... |
I have been reading about encrypting and authentication. Traveled the path from home made authentication to encrypt-then-mac approach and finally settled on GCM mode.
I am curious what resided inside aes_256_gcm.
What is obvious from the name: AES algo and 256bit key length.
IV len I could figure out from EVP_CIPHER_i... |
Basically, I want to use OpenVPN on a VPS to browse confidentially. However, I don't know much about VPS hosters and to me, it seems to be a hard choice because there are so many.
However, I think it's important to choose the right one because it seems to be pointless to set up your own VPN if the VPS hoster is willin... |
We all know there are still vulnerable code out there even though they may or may not get exploited and found for hacking attempts. I've seen people do it countless times and have a possibly plausible solution I've been working on for this. The only thing I lack is possibilities and opinions for this idea.
Based off of... |
Wikipedia reports
Currently, the best public attacks break 46 of the 64 rounds of SHA-256 or 46 of the 80 rounds of SHA-512.
What does this mean, and how safe is SHA-256 expected to be in the conceivable future? To a layperson, 46 out of 64 may sound like it's about "72% broken". Since Bitcoin relies on SHA-256, is... |
I have a server in a trusted environment. This server handles requests from clients in an a non-trusted environment. I'd like to authenticate each request and to know if the client code has been tampered or not.
Client software is installed in a secure environment and if I generate some 'secret' (nonces or pseudo-rand... |
I'm looking for a secure way to let users login on my website. Currently, I've always used a session system, like this:
<?php
session_start();
if (validPass() || isset($_SESSION['userId'])) {
if (isset($_GET['logout'])) {
session_destroy();
} else {
if (!isset($_SESSION['userId'])) {
... |
I have seen it presented as a special security technique but it seems like it basically means automated security monitoring of your virtual environment. Is that the basic idea?
|
I know it's generally said that storing user credentials in plaintext is a horrible idea. I'm in the middle of implementing Basic Auth over SSL and was wondering what I should do with the user credentials once they're decrypted. Once I decrypt from the wire, I need to make sure the credentials match what's stored in ... |
I am learning about XSS attacks. Wikipedia says that in a non-persistent attack an attacker may provide an innocent-looking URL that "points to a trusted site but actually has an XSS vector." What would this look like? Can someone provide an example?
|
I have been reading about the perils of not going the pages of my own encrypt-then-mac implementation, because there so many things can go awry. So decided to use EVP_aes_256_gcm.
But some questions came to my mind,
Is EVP_aes_256_gcm following some standard that would make it interoperable between different crypt tool... |
OpenSSH won't invoke PAM at all if public key (RSA)
authentication is configured and the client presents a valid key.
So if you use key-based auth, you can't enforce 2FA easily.
One workaround for this limitation involves writing a helper
program that will prompt for a Yubikey OTP. This helper program
is arranged to be... |
Say I wanted to avoid exposing a database primary key in a URL; somehow I must encrypt the key, so that the url only exposes elements of an unenumerable cipherspace. What kind of encryption should I use?
N.B. I'm aware that this is not the whole of a secure process. I would of course have to validate attempted access t... |
I've developed a website where people add their sensitive data. Not credit cards, but lets say they share things about themselves which are private and it wouldn't be good if other people see that info. Some of the data is private, some is public.
I want to keep the private data private as in... If someone breaks into ... |
I've read a few articles which suggest that somewhere around 30-50% of PC's are infected with malware. Supposing that means that hackers then have control of those computers to do as they please (root access), do they then have the ability to make requests to websites with the browsers saved passwords (or simply by usi... |
I've been told that black market websites that have pretty much every drug, guns and all sorts of illegal things for sale don't actually exist on the internet, and I was then told some lengthy explanation as to why they can't get shut down.
I'm talking here about websites such as Silk Road on Tor.
So why can't the gov... |
How do most teams handle the storage of passwords, in particular the required changes when team members leave ?
Right now, we use a centrally stored encrypted file but the thought of changing 100's of passwords when key employees leave is a bit overwhelming.
|
I would like to know if it's possible to stop a TCP SYN OR ICMP Flood attacks if these attacks are detected at time. What is the most accurate process to filter these addresses if the only way is to block the IP addresses of the botnet.
|
This is probably a naive question, but here goes: What is better for security over TCP/IP?
Encrypting the payload and then adding a checksum?
Checksuming the payload and then encrypting it?
Checksuming the payload and then encrypting it, then checksuming again?
Something else entirely?
And by security, I mean bad gu... |
Is it possible to get information about the hardware from an offline version of HKLM/SOFTWARE hive? There is OEMInformation in there, which gives things like machine manufacturer, but does the machine need to be on to get this information?
|
I can't seem to find a decent explanation anywhere of the practicalities of remote system administration (e.g. SSH) of an encryption-switch-encrypted SAN-stored infrastructure.
The environment will be NetApp SAN with SafeNet encryption switch and a vSphere cluster with numerous Linux VMs.
Note that it is the system adm... |
If a hardware blocker cannot be acquired could an investigator use DD without a write blocker, would that be forensically sound?
|
+--------------------------------------------------------+
| Client Host Name |.. IP Address ..|.... MAC Address ...|
| Desktop-Home ....| 192.168.1.100 | 00:19:D1:EA:03:68 |
| GT-S5380K .......| 192.168.1.105 | B8:C6:8E:4D:12:B1 |
Here you can see 2 things connected to my network (as seen in the DHCP Client... |
A somewhat related question has already been asked (What would one need to do in order to hijack a satellite?), only at a more abstract level.
Now we have a presentation by Hugo Teso from n.runs AG hitting the headlines and making some pundits from within the Beltway possibly blush, which does bring critical infrastruc... |
Is there a service/company which allows you to make anonymous payments online ?
This is how i want the service to work - Just like a credit/debit card. When you make the payment online, instead of entering your real name and real address, you enter the name-code and address-code issued to you by the service. To the re... |
Session Hijacking Prevention
It is good practice to bind sessions to IP addresses, that would prevent most session hijacking scenarios (but not all), however some users might use anonymity tools (such as TOR) and they would have problems with your service.
To implement this, simply store the client IP in the session f... |
Here is a theoretical setup:
You have a web server running Windows Server with IIS
You have a website running here which connects to a database
This website can start automatically when the server starts
The database connection is done using trusted windows authentication
A malicious party gets the hard drive from you... |
My debian server got exploited by some scriptiekiddie who used Newbie3viLc063
http://pastebin.com/jma8JRG1 .
Scriptkiddie uploaded logo_php.png to my server (My permissions sucked :s) and he did run it as php file.
And I have few question:
How can I delete/block backdoor what it did. I did block port 55555 (script use... |
I have been assigned the task of adopting and implementing a certain backup software solution for our GNU/Linux farm.
As per my deparment defined requirements, this solution should support SELinux enabled systems to be valid. After a not too thorough research, it was quite obvious that this product did not support SELi... |
I have a question about HTTPS, which I need help understanding.
So if I type: https://www.facebook.com/FOOBAR and as the connection is encrypted, will someone in the middle (say my ISP or someone who is trying to MITM attack) find out that I requested the FOOBAR resource or is everything encrypted?
TLDR; when making a ... |
My unpatched PC running Windows is connected to a network which contains other "infected" computers, can I get infected by viruses without any interaction on my part?
|
OWASP suggests that when implementing CSRF protection any attempt to go 'Back' in the browser will cause issues as Interaction with this previous page will result in a CSRF false positive security event at the server.
I've seen online banks handle this by destroying the session as soon as you hit back, but i'm wonderin... |
A discussion came up at work recently and a debate ensued regarding choosing a vendor. Several people were of the opinion that it is smarter and easier to choose a single security vendor for all our needs (lets say for example McAfee as they offer a large number of different products(and lets imagine that they don't ju... |
We have devices that can generate tokens. So we can use tokens with passwords to perform two factor authentication. There are many ways to implement such systems to enhance security. One of two I know, is to modify open-ssh client, and, another is to develop a PAM(Pluggable authentication module) module.
Are there othe... |
I just discovered that our server other's website for example: http://destiny.mbtosi.com/styles/new/images/no.png should say "This Web Page no longer exists." but in 50% hits it shows an image from kind tenant website. This image is not stored on our server and apache access logs does not list hits when image is displa... |
I'm trying to create a DFD for a threat modeling exercise. How much detail should I get into?
The SDL Threat Modeling guidelines state that I know that my DFD needs more detail when there is still a trust boundary in the DFD. Suppose there is a trust boundary between the datastore A and process B. Since there's a tr... |
In the "Hacking the art of Exploitation" its said that the basic idea of stack overflows attacks is that the operating system can't differentiate instructions from data inside the stack ,and the solution to this problem was to implement a "non executable stack".
My question is how is this implemented ??
|
Recently, while looking at some Perl CGI files, I came across this. I am not familiar enough with Perl to know exactly what it means, but I did attempt to base64 decode the string to no effect. Can anyone tell me what this is doing or what it means?
#!/usr/bin/perl
require './lib.pl';OFND('JmJhJÊ3ÝeWlpµTÞAKCk7ÇVBÖDQpp6... |
I'm sure everyone here has seen the rise and further rise of bitcoin. The process used for mining bitcoin is basically "let's brute force an SHA256 hash that is less than this amount"
That being said, it seems to really be getting popular. Now there are extremely fast ASIC miners out there that are capable of over 60,... |
I have a simple wireless router to share the internet with single access username/password.
I was wondering if it is possible somehow to set packet encryption so that other people on the LAN cannot sniff them?
|
Anyone knows where can I get materials/presentations/trainings from RECon 2012 and before? Is there any place where I could buy it or download it, if it's free - I doubt it, but who knows?
|
I am taking a security class. The class notes say that an attacker can observe a pattern in temp file names and then make their own temp file to compromise a program. They say that if a temp file is made using a process ID, an attacker could create a symbolic link
to a password file with a tripwire process ID so as to m... |
When I think of a script kiddie I think of someone who might barely research a tool then point it at a website - things like the recent question about LOIC come to mind when I think of that. A hacker (either black/white/grey), I imagine, is much more methodic and plans his route - they're running this system, with that... |
On an ARM Cortex A9 core, privileged instructions have to be executed so that unprivileged code can use performance counters. For instance with this GCC inline code, which would have to be run in a kernel:
/* Allow access to perf counter */
__asm__ __volatile__ ("\tMCR p15, 0, %0, C9, C14, 0\n" :: "r" (1));
/* Turn of... |
I am using IIS 7.5 and I want to impersonate users for my different applications in an intranet environnement. To do so, I am considering using the asp.net mechanism with the user/password in the web.config (encrypted), but I'm unsure about some possible threats. I'll explain it with a concept (I know my example is use... |
I want to make a browser extension available to users. Can I sign my extension so that users can verify it is authentic, without needing to trust the web site where they got the extension from nor the security of their network connection? Which browsers support signed extensions that are easy for users to verify?
|
I have a Debian installed. When there are security updates, I review and install them as soon as possible and think about using automatic updates.
From time to time I want to boot from a clean boot CD and check if the system has been compromised.
For that reason, I want to check if any packages / binaries have been mod... |
In computer security, we know that weak points in software are called vulnerabilities (if related to security). And once the vulnerability is found, theoretically it requires a piece of code as proof of concept (this is called an exploit). In this context, the term payload is also mentioned.
Then, what is the differenc... |
I develop a license server and a license client system (Java based applications).
The flow is the following:
The license is stored on the license server
The client application includes a license client component.
The license client connects to the license server via HTTPS to retrieve the license information.
The ... |
I have a question regarding your experience of TCP Sequence Prediction that I am hoping someone could help with.
I am aware of how TCP Sequence Prediction works and how the connection can be hijacked by an attacker predicting the sequence number and preparing a faked packet and so on, but how prominnent is this sort of... |
Is there a tool that allow the sharing of nmap scan results ? I know nmap can produce XML and I can easily convert them in HTML.
I would like to know if there is a tool with more features. For example, an online web page that would give users an UI to compare two different scan results from the same host taken at diffe... |
the other day at our bank, while my wife and i were transferring some funds between accounts, we found that on one of the accounts, a phone number that has no relationship to either of us was listed as being her personal contact number. the bank officer seemed to be unaware of how this might've occurred and didn't seem... |
A malicious user can use Base-64 or other encoding scheme to bypass web application input validation or to bypass some external Web application firewall. Since these encoding schemes are infinite how we can make these inputs finite to validate each and every input string.
|
The Augmented Reality games from Niantic, Ingress, (where players travel to specific GPS locations to destroy and rebuild virtual targets, link locations, and team up with other players in order to carry out missions) and Pokémon GO (a reworking of the original Pokemon game that requires players to physically move to t... |
I'm working on a site that doesn't need to be known to the Internet at large (but for a few reasons, is hosted on shared hosting instead of on an intranet). It's a WordPress installation and so I've set it up to discourage search engines and be fully password-protected.
I'm now looking at how I can harden it a bit more... |
I feel that this is definitely a hack of some sort and an interesting one.
I am using a Beetel 450TC1 ADSL2+ modem router and here is what I face:
* First, I disconnect the telephone line from the modem-router, reset it and then access it using the default user/password combination.
* I just change the admin password
N... |
I am trying to design an attack vector against an organization in which the pen tester (myself), steals NTLM credentials through HTTP. I am thinking of these scenarios:
1- I set up a web server on my machine and social-engineer the users to visit it.
2- I send an email with an embedded <img src="my.ip.address/x.gif"/> ... |
I'm developing a web API for a user database that will be used to verify a given username / password combination is valid.
I'm just looking for comments / criticism on the following method that I'm planning to use:
API Key records are stored within the database
Each API Key record consists of a public API key and a pr... |
I was reading this article from Life Hacker, How to Automate Your Phone for Every Room in the House with NFC Tags. The idea is to place NFC tags around your house, car, etc. so that you phone will automatically do some action when you touch the tag. Clearly, this seems to be a security challenge. In many ways it would ... |
While I primarily work with penetration testing for my company (A small/medium sized company with approx 50 employees), I'm also a part time member of their sys-admins team (it's handy to keep up-to date with server environments/networks etc). There is one manager in a remote office who "knows what is best" and always ... |
Seeing this comic from xkcd.com made me thinking:
Is extending the requirement of admin privileges to things such as connecting to the internet, running the web browser, reading browser and other software config files, etc, be something operating system developers and maintainers should be looking forward nowadays?
Or... |
Yesterday we got to know of a massive brute force attack on WordPress admin accounts targeting weak passwords.
From an online source:
A botnet using more than 90,000 IP addresses to crack WordPress admin accounts may be used as part of a larger plot to disrupt online users, according to researchers.
WordPress users wi... |
General
Always check the MD5 hashes of the .NET Framework assemblies to prevent the possibility of rootkits in the framework. Altered assemblies are possible and simple to produce. Checking the MD5 hashes will prevent using altered assemblies on a server or client machine.
Source: https://www.owasp.org/index.php/.NET... |
We are going to serve content to a Content Management System that embeds it through an iframe (yuck). Some pages that we serve need to be authenticated before – only a valid user should be able to see them.
The company who previously implemented what we're about to do did this through the requests. Of course, since the... |
I'm evaluating a credit card processor[1], and I noticed they are using MD5 as part of a salted hash algorithm to protect a secret key. Since I know MD5 is generally considered broken, this feels like a poor solution. Is that enough of a criteria to reject them as our processor? Is it possible to demonstrate an attack?... |
I am using VoIP for my office because I can use the same number whether I am in USA or anywhere else.
I am using it on my laptop and I have to visit India in the next few days. My friends say rules are regulations in India are not that organized and that my calls can be hacked in that country.
I have asked my VoIP pr... |
I was reading an article on WAF evasion techniques http://www.slideshare.net/devteev/methods-to-bypass-a-web-application-firewall-eng. The article discusses two techniques
HPP (HTTP parameter pollution)
HPF (HTTP parameter Fragmentation)
HPP was easy to understand but I am confused with HPF and what is the difference... |
Higher authorities could easily find out about criminal activity - such as drug trafficking and child pornography - being conducted on a laptop simply by hacking into it or somehow seeing the history.
However, the iPod Touch - or any tablet device that can access the internet that isn't a phone - is next to impossible... |
Imagine a generic web application with a login form to access the application. Regardless of how the actual authentication is performed, what are the implications of not checking the referer header to verify the submit request is coming from within the same application/domain/approved URLs?
Another way to think about ... |
I use Skype a lot. With all of my clients, staff, contractors and friends, however, the acquisition by Microsoft worries me, as two of my clients are direct MS competitors, and I often work on long projects which are in development for over a year before they are launched to the public and are therefore pretty sensitiv... |
Currently I have a bunch of servers scattered across a few different providers e.g. EC2, rackspace. Some boxes are Linux and some are Windows. Currently I'm finding the administration of the firewall rules to be quite labor intensive. Are there any solutions out there that provide a centralized management platform?
|
I've recently received two spam messages that show a possibly worrying degree of knowledge about my contacts, and I'm wondering how concerned I should be.
Specifically, the names -- but not the email addresses -- that they appear to come from are family members. They share the same last name as me, but it doesn't appe... |
Can a malware file have multiple "Hash values"?
|
While looking for solutions to entropy pool depletion on virtual machines, I came across an interesting project called haveged, which is based on the HAVEGE algorithm (HArdware Volatile Entropy Gathering and Expansion). It makes a pretty fantastic claim.
HAVEGE is a random number generator that exploits the modificati... |
Has anyone monitored various requests from all over the world on Port 17275 via UDP?
My firewall logs show huge amounts of such requests from lots of different IP Adresses.
I can't find any documented service which shall use this port.
Anyone knows what piece of software may cause these requests?
|
I'm writing a business-language report about MD5. In my search a found a paper by Yu Sasaki and Kazumaro Aoki explaining their 2123.4 pre-image attack on MD5.
I know that it has something to do with the feasibility (or in some cases, even the possibility) of an attack, but I don't have a sound understanding of what com... |
I am new to information security and analysis.
Recently, I came across FSDB (Foundstone database) and GHDB (Google Hacking database) while exploring the McAfee Foundstone Sitedigger tool.
What are FSDB and GHDB? And importantly, how can I use the information from these databases to learn about vulnerabilities of websi... |
I've read this interesting comment (about the security level, or lack thereof of some website built by a prominent chip manufacturer, an interesting discussion by it's own virtue, but not my question)
Here is the comment (the bold section is my addition)
So I thought I'd test it out a little more. Pretended I'd forgot... |
RAT (Remote Access Tool, e.g. Sub7) are considered malicious by Antivirus software. How can it distinguish between such patches and a client application for commercial software like NetSupport School?!
|
I have the following set-up.
Home pc ---reverse ssh tunnel---> to linux server
The reverse ssh tunnel is set-up so that on my home pc, port 22 is open, but I have nothing currently listening on that port.
My intent was to leave a VNC server running on that port (on my home pc), and have my linux server act as a middle... |
For example, if there is a network with three computers connected to the same switch, Alice, Bob, and Eve. If Alice and Bob add each other on their own ARP list as a static ARP entry, and Eve wants to do attack on the network connection between Alice and Bob, how could he do?
By the way, I am wondering if sniffing is s... |
I've got a class exercise that involves a virtual game of Werewolves/Mafia. We're not really taught how to do anything in this class, which makes it hard for everyone to do the labs.
The idea is that for certain rounds of the game, the bad guys vote for people to kill, then in the next round everyone starts guessing ab... |
How is with the support for ECC (Elliptic Curve Cryptography) in (Open)PGP so far? It seems that GnuPG (The GNU Privacy Guard) doesn't have an official implementation - but I did find the gnupg-ecc project (ECC-enabled GnuPG per RFC 6637) on Google Code:
This project brought to life Elliptic Curve Cryptography support... |
Is there something like OWASP for Network Security ? Or have anyone of you come across a testing guide for network security, as to how to start an audit and then the minimum number of tests to run and the tools to use ?
I am trying to put together a document and it seems that the number of tests to be performed are en... |
I am trying to classify network protocols over network traffic . Now my task is SSH protocol. I read the RFC and know SSH starts with protocol exchange message from both client and server .
Format is : SSH-protoversion-softwareversion SP comments CR LF
Also I found an open source project called "ndpi" which already im... |
I am testing a web application for click-jacking vulnerability. The attack works fine for single clicks, however i am trying to delete a file and the hidden frame (victim) throws a pop-up confirmation.
Is there any way to hide the popup(same as of frame) and trick the user to accept it. I have googled a lot but no luck... |
I have an external multimedia hard drive (1.36TB). I made 4 partitions of 350GB each. Then I shredded the free disc space of all the partitions.
Now I want to put Truecrypt on the disk. I can't put it on all 4 Partitions. If I put it on all 4 Partitions, I can't use the hard drive for watching TV or films.
So I wan... |
A lot of discussion I see suggests that changing default ports for services is just "security by obscurity" and is easily defeated by scanning for open ports.
My question is this, though, if the port is changed to a random port, yes an attacker knows it's open, but do they know what service is listening? And if they d... |
So I have a SOAP message like this (key data and encrypted data has been truncated):
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" xmlns:a="http://www.w3.org/2005/08/addressing" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
<s:Header>
<o:Security... |
There is two-step authentication available at gmail and outlook as well. There are some using it, but the majority doesn't. In what cases it is recommended? If I have a strong password what are the chances of abuse?
|
I've been thinking recently if its possible to DNS spoof an external network. Let's say for example you are attacker.com and your victim is of course victim.com. Then I've thought of 2 scenarios:
1. You somehow manage to find victim.com DNS server, poison the cache there and just wait for your victim to connect
or 2. Y... |
How secure is passwordcard.org? Assuming user follows recommended precautions:
Don't read along with your finger, or the smudge will tell a thief where your password is.
Keep your PasswordCard on your person, don't leave it lying around near your computer.
Clear your browser cache and history after printing this page.... |
I am having trouble and need some direction using computer certificates with Windows 7 firewall IP Security rules, using certificates only for user authentication. I can get everything to work correctly using a passphrase for user authentication. However, I would like to use certificates.
I cannot find any documentatio... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.