instruction stringlengths 24 29.9k |
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Currently with apache/mod_ssl, if DHE is enabled then a 1024-bit ephemeral key will be used. I found the following quote in Adam Langley's blog:
Ideally the DH group would match or exceed the RSA key size but 1024-bit DHE is arguably better than straight 2048-bit RSA so you can get away with that if you want to.
So i... |
I plan on creating a domain user account that will be able to log on as a service, but have only the minimum requirements for this service to function. of course this could be misconfigured, but assuming I don't add a user that has too many privileges are there an inherent security risk involved?
I couldn't find an ... |
Is there an accepted naming convention for referring to PKI artifacts?
There seems to be a lot of confusion with the naming of artifacts. For example, it seems that some people refer to:
public keys as certificates
public keys as public keys
certificates as public keys
certificates as certificates
private keys as k... |
I have just been doing some penetration testing on a site, and I have noticed (and I have noticed before but now seems like a good point to bring it up) that putting a null byte in the search string actually terminates the string there.
That is fine for the lower level languages like C, I know how that works, but why d... |
I have a strategy consulting and sales background, but what I read about IT and IT Security sounds fascinating as an outsider. I'm considering a career switch, but would need to know quite a bit more.
IT Security is what interests me the most, but do I need to learning a programing language? If so which? Do I need to ... |
I received an email earlier today from my ISP (a university). The email reads (in part):
Your network connection has been disabled because your version of Java is not patched for the most recent security vulnerabilities. This leaves your computer open to attack. If these vulnerabilities are not patched, your computer ... |
Due to a potential NSA backdoor, the NIST is now recommending that implementor no longer use ECC-based PRNG Dual EC DRBG.
(As described in Wired.com) this PRNG has certain features such as:
continuous testing of output
prediction resistance
re-seeding
... possibly others
Question
Now that other PRNGs will be used... |
Can you correct me on this. I create a keypair on my PC. Copy the public key (append to authorized_keys) on the server. Disable password auth on the server, and SSH to server from my PC. I have the public and private keys on my PC.
Do I need the public key anymore on my PC to connect?
If someone gets the publi... |
I'm trying to implement return-to-libc,
here's the code
void func(const char *str) {
char buf[4];
strcpy(buf,str);
printf("you entered [%s]\n",buf);
}
int main(int argc, char *argv[]) {
if(argc != 2) {
printf("Need an argument\n");
return 0;
}
func(argv[1]);
return 0;
}
Now... |
I'm working on access control system and on analysis tools for reasoning on it. In A.C. system based on policy, think about XACML specifications, the overall behaviour of the system cannot be clearly predict in case of multiple policies, also maybe conflicting.
Thus, my question is, from a developer side or a security... |
Where can I upload a list of my friends and get a list of their keys found on keyservers?
Here are some key servers:
http://keyserver.ubuntu.com:11371/
http://pgp.mit.edu/
https://keyserver.pgp.com/vkd/GetWelcomeScreen.event
If I had nothing to do all day, I could open my address book each week and paste in each of ... |
I am going through training in information security, as a part of the course they included compliance standards like:
PCI DSS
ISO 27001-2005
Cobit framework
So after searching over Google, I came to know that it is for "IT auditors" (correct me if I am wrong).
In layman terms, what is the job of an IT auditor?
|
From what I understand it is bad security practice to display informative failed login messages like:
The email you entered does not exist
Instead of
Incorrect email/password combination
because it can lead to username enumeration. Is this is really an effective way to enumerate logins? It seems like the only way... |
In regards to security, Why is one-time pad encryption unconditionally secure against eavesdropping?
Also, why does the triple DES use an Encryption-Decryption-Encryption combination rather than an triple encription combination?
|
Supposing I have generated random data from CryptGenRandom (or similar PRNG), at what point does futzing with the values make it not-so-random that it's useless? Or is sufficiently random in enough to make it sufficiently random out?
Basically I'm looking at a key generation algorithm that generates an 8 digit 0-9 valu... |
My university has a wireless network I log into with my username and password. It's using PEAP. My phone and laptop automatically connect to this SSID when they detect the network.
If someone sets up a hotspot using the same SSID and my phone or laptop see this SSID, they are going to connect to this network, assuming ... |
I understand that passwords with varying cases (upper and lower) as well as numbers and special characters are much "stronger" and harder to crack than those that are short and all lowercase or whatnot.
However, I wonder why is everyone adopting this as a standard for their passwords, even on unimportant sites that hav... |
I was reading some e-books to understand the basics of block ciphers and how it works in AES. As i understood, Permutation plays a big part in AES and Block Ciphers,
Here is what i understood by permutation,
A permutation is an ordered arrangement of the elements of some set S
Let S = {a, b, c}
c, b, a is a permutation... |
I was pen-testing a site recently which I found a few issues in, and this continues to a previous question I asked about Null-byte string termination in web applications.
I have noticed that the site does not filter out URL Encoded CR/LF characters, and if I inject these characters, they do get respected in the source ... |
This has been rewritten because at first I thought this may be an accident but now it’s clear there’s a security compromise.
In my Google Calendar I noticed an event that occurred each day from 11am-12pm titled "Hey man how you doin'". It had the description “How you doin ??”. I did not create this event. I tried dele... |
Assuming a secured page https://google.com/redirect.php?keyword=apple which redirects the visitor to a non-secured website http://apple.com, would an eavesdropper (anyone watching over the network) be able to see the keyword "apple" from the referer URL?
|
I recently read that the Flash plugin ignores the Content-Type header in certain circumstances. In particular, you can give Flash a URL, and the Flash plugin will happily fetch the content at that URL and load whatever it receives as a SWF file, with the permissions of the site that the content was loaded from — even ... |
I currently have some Vps's and shared hosting plans with a few hosting providers. Recently one of my shared hosting accounts was suspended due to a denial of service attack. I understood why they had to suspend the account etc. But what I was curious of was how do they know which website was the victim? It is on a sha... |
I was directed here from the Unix & Linux site. I've gone through some of the related questions, but they seem to be more concerned about whether a guest OS can access the host OS in someway. Since it doesn't seem very likely, I'll tell you about my requirements.
When the user puts a USB memory stick in a USB port, the... |
I have an application which is hosted on a windows server on which an SQL DB exists. This server communicates with the clients and agents installed on host PCs through TCP/IP and SSL connections. I'm currently focusing on any security features related to the Database. What are the main requirements needed to be able to... |
Suppose I send a PGP-encrypted email to person A, and the same email
(same subject line, same message text) unencrypted to person B.
Suppose a secret service intercepts both messages.
The secret service rightly assumes from the identical subject line that both mails
contain identical text.
Does this make it possible f... |
I've checked my Linux server (Centos 6) with rkhunter. I found the following in rkhunter log
[14:38:54] Checking if SSH protocol v1 is allowed [ Warning ]
[14:38:54] Warning: The SSH configuration option 'Protocol' has not been set.
The default value may be '2,1', to allow the use of protocol vers... |
I am doing an internship at a big company wich create industrial automated systems for some big company's. They want me to design a way to monitor all the Java based control modules. Now I am going to use JMX, but I have thought of a couple of ways of doing that, and they all include opening some ports. I was wondering... |
Since trying to patch, we can not access the Web Interface, the Console page is empty.
We also tried to upgrade trough CLI but it returns this error messages
Checking for undeployed changes...
Found undeployed changes!
[PATCH_UPDATER] [ERROR] The patch cannot continue because you have undeployed changes in your system... |
I am working on an SSL implementation project and ofcourse I need to verify the certificate presented by the server. To do that I need CA certificates or at least root CA certificates (correct me I am wrong) but I cant seem to find any source which can give me certificate database. Where can I find all these certificat... |
I'd like to generate a bunch of keys for long term storage on my MacBook.
What's a good way to:
measure the amount of entropy and ensure it is sufficient before each key is generated, and
increase the entropy if needed?
Something similar to Linux's /dev/urandom and /dev/random…
|
Recently I am studying ISO 9798-2 Three-pass mutual authentication. There are 3 steps, as following:
B -> A: NB // B sends to A a "nonce" value NB
A -> B: {NB||NA}K // A's identity is proven to B by showing B that A has the correct pre-shared secret K to encrypt the challenge NB.
B -> A: {NA||NB}K // B authenticates i... |
I am somewhat confused in terms of how secure Android OS is and how updates work on Android. Are there security fixes on each release? How can I keep track for Android exploits and what are the most common attack vectors for Android devices. Any decent books on Android Security?
|
Background
I would like to setup a honeypot server on a Windows 7 PC.
My system is not part of a network and I don't run a server.
I have a Windows 7 desktop PC.
It's Home Premium Anytime Upgrade 32-bit OS and 32-bit PC.
I don't have a wireless card.
I do have a wireless router and its D-link DIR-815.
I do use my... |
I've always heard that scrypt was better than bcrpyt... because of memory causing GPU a very difficult time to crack. However, the notion always was that scrypt hadn't been tested, it was kind of a new crypt method, and that I should wait it to be tested before using it.
Has that time come where people have made scrypt... |
If I had to store credit card details temporarily to shove it to the processor using an asychronous worker, I know that that information must be encrypted.
To get it to the worker, however, it must be stored at least in RAM. How is it possible to do this but remain PCI compliant? This states:
3.2.2 Do not store the ca... |
My boss is trying to invest on a CCTV solution that he orders from China, his idea is to market it here after we fine tune the process and configuration and make a few tweaks of our own.
It consists of 4 wireless cams and a reception device(that I think has an Android port) that is connected to the internet, then they ... |
Is it illegal to impersonate user-agents when you are crawling a website?
If so, what and how a legal action can be taken against the faking requester? Is this law applies only for crawlers or a user impersonating a browser from a different browser(changing user-agent as firefox but making the request from chrome)?
|
When you add the /gs argument to microsoft's compiler, it would place a copy of args below the buffer variable.
So, what's the point of keeping a copy of arg?
|
I want to have a secured call over internet between two android phones. I have found SipDroid which is an open source SIP client for Android. And also I have followed this to install Asterisk, Dahdi and LibPre on my Ubuntu 10.04.
I want to have it configured it for Local Lan first, although it is intended to work in th... |
Maybe you could help me with a small problem.
Would you recommend IPSec or TLS for a Server-to-Server-Connection? I need two or three arguments for reasoning a decision within my final paper, but sadly didn't find a criterion for an exclusion. The reflection of IPSec and TLS within my thesis is only a minor aspect, the... |
We know mifare Classic has been broken.
My question is, say I store encrypted data (using some out of band RSA encryption) instead of plain data on Mifare Classic card.
And also store a signature over this data on the card.
Does this make Mifare Classic secure?
|
I have a server on my DMZ whichs relays syslog and OcsInventory messages to a server on a vlan for logging servers.
In order to allow the packets to go through I must allow port 80 (OcsInventory) and port 514 udp from this DMZ server to the machine on the vlan.
If the machine on the DMZ were ever compromised an attacke... |
As I understand it, a certificate is used only for verifying the identity of the server. Are there any security benefits for changing them frequently (once a week for example)?
If this is done so that a new symmetric key can be negotiated for each session (for perfect forward secrecy (PFS), say), can't it be done witho... |
True Scenario:
Representatives from the GCHQ went into The Guardian newspaper corporate office in London and demanded top secret data (leaked by Edward Snowden) be returned to authorities. The senior editor did not comply with the request to turn over the laptop, but agreed to have the machine symbolically destroyed b... |
I have encountered a supposed low level eploit on my network at work, by the name of: Exploit.LNK.BadLnk.a (v). I have torn through pages of entries on google trying to find information on this bit of malware. The only entry that actually pertains to this one points to a report on www.sunbeltsecurity.com with an entry ... |
My company has a PCI compliant billing gateway and they expose a service for submitting credit card payment details.
I am writing a (Single Page Application/end-to-end javascript) website for them that is on a different domain than this billing gateway so naturally calling this service from javascript in the client (b... |
As I use my Paypal account for various online services, I noticed that vendors integrate differently with Paypal for on-demand payment, and scheduled payments.
I also noticed that Paypal offers a "verified ID" service so that we can be sure that the proposed paypal account is truly who the user says they are.
I haven't... |
If it's true you only need about 128 bits of entropy to fuel enough data forever, why is it that /dev/random is so slow? My system has uptime of 214 days!
Is it really only gathering .000000001 bits of entropy every sample? Shouldn't a mere jitter reading from the kernel provide at least 1 bit of entropy? Hasn't it ... |
I am trying to figure out what would be the 'perfect' authentication system for a website.
On one end, we know that simple hashing algorithms can be brute-forced or cracked in other ways. Hence why MD5 is no longer recommended. The best solution for secure password storage, it seems, is making use of key stretching in ... |
I would like to know can an Network Intrusion Prevention System[IPS] be used as an Network Intrusion Detection System[IDS] and vice versa.
Can the Host based IPS be used as a host based IDS and vice versa ?
Is it necessary to have both IPS and IDS ?
Which one is more reliable Network based IPS /IDS or host based IPS/ID... |
I am trying to develop a PHP function to calculate NTLMv2 hash by providing server & client challenge, domain, account and password. The resulting hash appears to be not correct. Can someone guide me about the correct way:
Here is the algorithm in PHP language:
function GenerateNTMLv2($password, $account, $domain, $cl... |
In CERT secure coding standard, there is a recommendation that "Always specify void even if a function accepts no arguments". A possible security vulnerability is proposed in it.
/* Compile using gcc4.3.3 */
void foo() {
/* Use asm code to retrieve i
* implicitly from caller
* and transfer ... |
How can I force my Chrome broswer (or even Firefox) to always use a higher security encryption?, for example 256bit (or more) encryption when using https.
I guess it should be some flag to force the negotiation.
I know it also depends on the other side of the connection.
I'm using Windows 7.
regards
|
Let's say that I am a Federal CIO and need to respond to a request for information on the architecture of a financial management system. I want to demonstrate that the system is capable of supporting multiple customers, can scale to thousands of users, includes modules A, B, C, D, etc., is interfaced to systems X, Y, ... |
How secure are car remote keys? When you lock or unlock your car, can someone spoof or make another remote key?
How do car remote keys work? Do they use some kind of private/public keys, encryption?
Are aftermarket alarm remote keys less secure than the manufacturer remote keys? I am mostly interested to find out if it... |
If a company has offices way up in a skyscraper, is it acceptable to have an open network without a password, as an easy-to-use courtesy to visiting guests?
The only ones that possibly would be able to leech off this would be the company on the floor below (or guests visiting them), which probably wouldn't happen sinc... |
Two users on my domain are receiving spam emails that have both of their emails in either the To: and/or CC: fields. There are many other users on the domain, but only these two are receiving spam emails. The two accounts are not exclusively linked or associated (eg. only two of them belonging in the same group)
Over ... |
We have a web application that we run for clients at their booth on fairs. The communication between clients and the server was done over HTTP until recently.
We're currently working on improving several security-related aspects of this application. For example, I now implemented support for HTTPS and wrote a small scr... |
Let's suppose that I have a simple application which is sending data to the server (placed not in my network), for example 0 1 2 3 4 5 (explicit data) in one second delay between each other. Is it possible to intercept part of this data, modify it and send like it was send by my application? How to do this? What should... |
Is it a bad idea from a security perspective to host both a publicly accessible website and a website that is only intended to be used internally on the same server? Obviously the web server would be configured to only allow access to the internal web application to specific internal IP addresses.
Are there any securi... |
I've read this nice question:
Should SSL be terminated at a load balancer?
And I have the same question, but with PCI-DSS compliance in mind.
Is SSL terminated at the load balancer, with clear communication between the load balancer and the web servers, PCI compliant?
I'm using AWS Elastic Beanstalk, which under the ho... |
If I enable Google Analytics on my web application, does the Google Analytics Javascript collect any information on the web page (any of the content on the page)? Does it collect any information about the GET parameters in the URL or the POST parameters for the page?
I've done a lot of Googling and found a lot of refe... |
I would like to perform some benchmarking of different block and stream ciphers for general data (lossless and lossy data) encryption and decryption (with focus on power consumption).
To get general idea, I guess it probably would be better to use existing tools than to implement everything myself. After that, I can im... |
I have looked at a few other questions related to this but nothing specifically answered what I was wondering about.
Say for example you have a server that is infected with a php shell such as c99. I have googled around and seen scripts that remove shells named r57, c99 etc. So my question is; is the only way these sc... |
I'm on a coffee shop wifi. I just typed https://google.com in to my browser and noticed that I got redirected to http://google.com. I tried other google domains (google.ie) and these work fine, so presumably they're black listing certain domains.
What are the likely techniques for the owner of this wifi to achieve this... |
Unfortunately, endpoint security is so terrifically weak that NSA can frequently find ways around it. -Edward Snowden
Would it be safe to assume that every popular linux distro out there has a backdoor in it that got there by people connected to US intelligence?
I think probably most of them yes, purely logically spea... |
Scenario: I just took 1 page of text (.odt) and copied it into a plain text document, that happens to result in a 3KB file.
With that as a random size criteria for discussion, CAN code be written to hide that document in firmware such that it can be accessed, edited with a plain text editor, and then put back, as a mea... |
Given this C program:
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv) {
char buf[1024];
strcpy(buf, argv[1]);
}
Built with:
gcc -m32 -z execstack prog.c -o prog
Given shell code:
EGG=$(printf '\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\... |
I am starting on sqlmap, and have dvwa for practicing web app penetration.
I am having the error "Could not connect to the database - please check the config file."
Not sure what the problem is but I have been searching. Nothing seems to be working. I have mySQL running on Linux, created a database.
|
I need to allow users to upload files with sensitive data to a server, then invite other authenticated users to access specific files.
This is my proposed solution:
Each user will have his own folder to which he uploads files, and the parent folder will have an .htaccess with deny all to block direct access. (This alr... |
I'm having trouble designing a system for authenticated content from my site distributed by other people. I'm working in Ruby on Rails, but I don't think that at a theoretical level my question isn't restricted to that framework. In order to not give too much away, my site (let's call it www.site.com) helps businesses ... |
I'm trying to understand How google authenticator - counter based work. I have tried googling around finding a demo or at least how this work. I understand its a one time password but not like TOTP. I am already working on TOTP but i'm terribly having issue with time sync, because i'm working on an offline PC. So the w... |
Generally, despite running hardware+software firewall combos and keeping every layer 7 aspect of the box secure, I don't like to disclose the direct IP addresses of our servers to the public as a further layer. That being said in order for mail to be sent most ISPs are requiring that the PTR record for our server match... |
I'm using privateineternetaccess to VPN my internet connection. Recently I've noticed some web sites appear to know my real location and IP address. The most alarming incident I've seem to have been resolved but I don't understand why it happened and was hopping someone could shed some light.
I had just cleared my brow... |
Referring to the security experts who demonstrated taking control of two popular vehicle models using a laptops connected to ECUs (http://www.bbc.co.uk/news/technology-23443215), what are the possibilities that there can be malware/trojans etc. written to infect vehicles?
I don't even drive yet, so I'm no expert when i... |
I have created a white-box fuzzer by extending the Crest.
Now, I'm looking for a test suite (a set of c programs with known vulnerabilities) to test the functionality of my tool.
where i can find such benchmarks?
|
I am in the following setup: given department ids, employee ids and file ids I want to check whether employee xy of department AB is allowed to access file f.
E.g. department id = "012", employee id = "123" and file id "012"
Then the application of Luhn's algorithm to "012123012" or some variation of the algorithm
sho... |
Given everything that is suspected about NSA (and GCHQ, DGSE, etc.) access to user data:
Avoiding speculation, can and do we know whether Google's recent action to make all searches use SSL encryption will actually prevent said spying?
If not, what more (in addition to what we've seen) would we need to know, to know t... |
Not completely au fait with PCI compliance, however we have our server checked each month by our host to check it is PCI compliant, because we have to keep it PCI Compliant for a specific customer/service that we have running on it.
We have another service on the same server/system that creates images containing custom... |
As part of an application I am developing, I am required to store user email adresses on a cloud DB.
The email address is not required to be in plain text for the normal operation of the application.
So, to provide security, the email address is being encrypted and then stored in the database.
The email address in the... |
I want to trial a HSTS policy on my blog without enabling it site wide initially. As a HSTS policy is just a HTTP response header would there be any problem with sending the header in PHP like so:
header("strict-transport-security: max-age=600");
The site will redirect any http:// request to https:// and I realise tha... |
If I know someone's ip, mac addresses and a computer name in a local wifi network, and also that there is skype running on their computer (and port), can send them a message through skype? Can I find out their skype user name?
|
I know that its possible to spoof a mac address out to a network. But is it possible to spoof the address, so that the Windows operating system and applications running on Windows see a spoofed address as the physical address for the network card?
|
A: running an OpenBSD machine with a httpd and a smtp server?
vs.
B: running an OpenBSD machine as virtualization host with QEMU having two guest OpenBSD system: one for smtp and one for httpd.
Q: Which solution provides more security? For first look, I could think that Virtualization is another layer of security ... |
After reading this article about RSA advising its customers not to use the default random-number generator in its encryption products - amid fears spooks can easily crack data secured by the algorithm, what products need immediate attention and configuration change? Does it affect the hardware token generators used for... |
I'm making a web application to provide intermediary service for customers to facilitate their interaction with a set of other web applications.
A simplified example would be to let a user access his emails from my site. For this I will need his email and his email's password. To prevent the user from needing to retype... |
I read this article a moment ago: http://www.geek.com/news/the-pirate-bay-is-now-hosted-anonymously-in-the-cloud-1522725/
But it was very light on details. Is an architecture as described in this article even feasible? If so, what are the benefits opposed to using a self-owned/hosted server with no logs and encrypted h... |
The first comment under this question states:
There are "smart jammer" techniques that are designed to mess with the protocol operations, not overwhelm the receiver with noise (e.g., for 802.11, you can disobey inter-frame spacing rules and spoof RTS/CTS messages to make the channel look busy all the time). These tech... |
This is my scenario:
A CA signs a certificate with its private key and sends it to a client via https response. From this response the client creates a X509Certificate2 class, that represents the certificate in .NET
X509Certificate2 myCert = new X509Certificate2(certBuffer);
I also have the CA's public key to verify t... |
Is there any plugin out there which prevent reflected XSS? Plugin could be either for firefox or chrome.
Thanks.
|
I know how to check this setting in code, and I know where to look in the web.config, but I can't seem to find information on how a vulnerability scanner like Qualys would detect this.
I've considered the following, but I have no way of knowing if my guesses are any good:
Is there an http header that is sent from the... |
I totally understand the basis of origin policy and the reasoning why all modern browsers have put this policy into place.
My question I guess is, do older browsers support this, and if they don't, could mean that people can create AJAX requests and target these requests to my website using an older browser?
The reason... |
I wanna give a filtering system in my script.
here it is :
<?php
$allowedExts = array("gif", "jpeg", "jpg", "png","bmp");
$temp = explode(".", $_FILES["file"]["name"]);
$extension = end($temp);
if (in_array($extension, $allowedExts)){
//here is rst of codes
?>
Means my script will check extension for uploading file w... |
I was wondering if turning on Airplane Mode really disables all wireless connections.
If so, anything you do on the phone locally can not be traced, seen, or viewed, hacked, etc. by anyone over a network. Correct?
That is I can privately work locally without a network state, data submitted via programs through the web,... |
Sometimes I need to use Internet from cybercafes or restaurants.
I'm concerned about the security when accessing critical sites such as my bank, Paypal or just my Facebook.
Besides the typical security measures (such as antivirus) I'm considering to use a VPN connection to avoid man-in-the-middle attacks and honeypots.... |
I don't want Google Chrome saving my passwords, I only want it to save my username.
Any suggestions?
|
The way DNS works, resolvers cache query results per TTL defined in the response. Consider an authoritative DNS server that is compromised, its main A record set to a different IP and TTL of that record set to something very high (like a month).
Is there any mechanism/process which would invalidate the cache of all tho... |
In an office work place, can a network admin have access to my Skype chat history and web browsing history without logging in to my pc since all pc's are connected with the same network?
i am wondering weather is it secure to keep my login details saved in a office computer?
Can our skype chats be read in real-time wit... |
I see a lot of these messages in /var/log/messages of my Linux server
kernel: nf_conntrack: table full, dropping packet.
kernel: __ratelimit: 15812 callbacks suppresse
while my server is under DoS attack but the memory is not still saturated. I am wondering what is the significance of the message and how to counter po... |
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