An attempt to exploit a weakness in a system, either for nefarious or research reasons. Questions with this tag should be about designing, carrying out, or defending against the attack itself, rather than about the underlying weakness.

learn more… | top users | synonyms

89
votes
2answers
29k views

What are rainbow tables and how are they used?

Where can I find one? Is there a pot of gold at the end? How do I protect against them? From the Area51 proposal This question was IT Security Question of the Week. Read the Sep 09, 2011 blog ...
216
votes
4answers
95k views

SSL3 “POODLE” Vulnerability

Canonical question regarding the recently disclosed padding oracle vulnerability in SSL v3. Other identical or significantly similar questions should be closed as a duplicate of this one. What ...
74
votes
4answers
11k views

Can anybody explain XSS? [closed]

I work programming Enterprise Java applications and do very little web development in 2002. I'm interested in security and like to read articles about it. However, I never fully understand how XSS ...
28
votes
4answers
6k views

Why is using salt more secure?

Storing the hash of users' passwords, e.g. in a database, is insecure since human passwords are vulnerable to dictionary attacks. Everyone suggests that this is mitigated via the use of salts, but the ...
64
votes
18answers
5k views

What security resources should a white-hat *developer* follow these days?

What sites, twitter accounts, FOSS software should a white-hat code 'hacker' follow these days? Do Include: Late breaking information on new security issues (RSS, Twitter, etc) A website that ...
25
votes
3answers
7k views

How do DoS/DDoS work?

In the last days one could frequently read about attacks from anonymous and LulzSec against different platforms like Sony or HBGary etc. Yesterday for example they DDoS'ed soca.gov.uk and jhw.gov.cn. ...
24
votes
1answer
14k views

Are SSL encrypted requests vulnerable to Replay Attacks?

Are SSL encrypted requests vulnerable to Replay Attacks? If so, what are good options to prevent this?
110
votes
9answers
126k views

Can webcams be turned on without the indicator light?

I've made a series of penetration tests in my network and one of the things I've tried was to record webcam and microphone. Recording an end-user's microphone seems to be a stealth thing, but what ...
60
votes
8answers
14k views

Should I change the default SSH port on linux servers?

Is there any advantage in changing the SSH port, I've seen people do that, but I can't seem to find the reason why. If you have a strong password and/or a certificate, is it useful for anything? ...
1
vote
2answers
704 views

Attacking a server on port 80 while only port 22 is open on the firewall

There is a question bugging me a after reading on network security. Theoretical situation: there is a packet-filtering firewall, which only accepts tcp/ip communication with destination port 22 on a ...
2
votes
5answers
400 views

Methods used to reverse a hash

I know that a hash is a one-way-function and that therefore there isn't a reversal function. By reversing a hash I just mean to find some plaintext that gives the hash. I think that I understand that ...
126
votes
8answers
15k views

Are “man in the middle” attacks extremely rare?

In "Some thoughts on the iPhone contact list controversy and app security", cdixon blog Chris Dixon makes a statement about web security Many commentators have suggested that a primary security ...
26
votes
6answers
31k views

Security risk of PING?

I have been told that PING presents a security risk, and it's a good idea to disable/block it on production web servers. Some research tells me that there are indeed security risks. Is it common ...
23
votes
5answers
28k views

Can I detect a MITM attack?

Based on this question here: Are "man in the middle" attacks extremely rare? Is it possible to detect man-in-the-middle attacks, and if so, how would one go about it? In addition, what if ...
19
votes
6answers
3k views

What security risks does IP spoofing bring?

By manipulating the TCP packet and changing the source address one is able to spoof the IP. As I understand it, you will not be able to set up a full handshake by doing this, as you will never receive ...
24
votes
8answers
18k views

Can I detect web app attacks by viewing my Apache log file? [closed]

I occasionally get clients requesting I look at their access_log file to determine if any web attacks were successful. What tools are helpful to discern attacks?
15
votes
3answers
14k views

Does X-Content-Type-Options really prevent content sniffing attacks?

In Tangled Web Michal Zalewski says: Refrain from using Content-Type: application/octet-stream and use application/binary instead, especially for unknown document types. Refrain from returning ...
30
votes
20answers
5k views

How can I prevent my kids from bypassing my computer restrictions?

My son has a downloaded copy of Ubuntu that he uses to "break" into my computer, bypassing Vista. I have two questions: Can this damage my computer or corrupt my files? (I have lots of pictures) Is ...
10
votes
2answers
9k views

How can someone hack my PC if I am connecting to the internet through NAT?

If I own a private IP address, 192.168.2.1 for the sake of it, and I am physically connected to my router, which it's internal interface is 192.168.2.254 and it's external interface is some public IP ...
94
votes
9answers
184k views

Where can I find good dictionaries for dictionary attacks?

I’m wondering where I can find good collections of dictionaries which can be used for dictionary attacks? I've found some through Google, but I’m interested in hearing about where you get your ...
43
votes
5answers
7k views

New XSS cheatsheet? [closed]

There is a great list of XSS vectors avaliable here: http://ha.ckers.org/xss.html, but It hasn't changed much lately (eg. latest FF version mentioned is 2.0). Is there any other list as good as this, ...
69
votes
5answers
15k views

Found suspicious, obfuscated PHP file. Is this a hack attempt on my website? [duplicate]

I just noticed that the top line of my index.php file got changed to what's below. <?php ...
17
votes
5answers
1k views

How to best defend against Targeted Attacks?

We have seen this attack method grow as part of Advanced Persistent Threats (operation Aurora against Google or the G20 French Finance ministry attacks come to mind) but I have no doubt that even ...
7
votes
4answers
951 views

Security attacks on PHP web applications

I know about following security attacks on php applications (html,php,js). XSS SQL Injection CSFR Session Hijacking /Fixation Code Injection Remote file injection Should i know about any other or ...
11
votes
2answers
25k views

Advice on what to do after being hacked? [duplicate]

After running a system scan earlier today, I found that my computer had been infected by a trojan horse. My reason for running the scan was because Windows kept shutting down and then recovering. ...
32
votes
3answers
30k views

How to exploit HTTP Methods

Many security scanners like nikto, nessus, nmap, and w3af sometimes show that certain HTTP Methods like HEAD, GET, POST, PUT, DELETE, TRACE, OPTIONS, CONNECT, etc are vulnerable to attack. What do ...
18
votes
1answer
3k views

Collision rate for different hash algorithms

Is there any collision rate measure for popular hashing algorithms (md5, crc32, sha-*)? If that depends only from output size, it's quite trivial to measure, but I suppose that depends also of ...
14
votes
5answers
3k views

Access to a router's GUI

During a recent visit to a coffee shop, I noticed that they hadn't bothered changing their default user name and password for their router. I realise that someone could log on and be annoying to ...
20
votes
5answers
22k views

How to simulate DDoS attacks from the Internet?

The idea behind security tests is easy. You want to know what a hacker can do - you hire a security expert who acts like a hacker to see how far he can get. You want to know what an evil admin can do ...
3
votes
3answers
6k views

FIN Attack- What is this type of attack really?

I just wanted to know what exactly is the FIN attack. I know about the FIN flag that is used to indicated the closing of a connection via TCP. But what exactly is FIN attack?
11
votes
4answers
444 views

Resources for data on security incidents

What resources exist to research data on actual security incidents? I would prefer an online resource but offline resources are acceptable. The cost of access should be less than $100 (US) for ...
8
votes
5answers
7k views

What kind of attacks against home router's NAT do exist?

I always thought NAT was some kind of a security feature and I still think it is, because if it didn't existed the internet, respectively the clients behind NATs, would be even more insecure, since ...
20
votes
4answers
4k views

Example of a backdoor submitted to an open source project?

To clarify immediately, I'm not interested in writing a backdoor. I have no interest in submitting backdoor changelists to projects myself. I'm researching some source modeling techniques, and we're ...
12
votes
5answers
7k views

What is a DoS Attack and how does it differ from a DDoS attack?

Can some one explain to me the concept of Dos Attacks for web applications ? Also what is the distinction between Dos and Distributed Dos ( ie DDos) attacks ? Wikipedia says : In computing, a ...
7
votes
1answer
9k views

Server attack attempts, what are they trying to achieve?

Recently, I have got a few 404 errors where the user has requested PHP pages. The URLs are range around the cgi-bin and php versions, eg, /cgi-bin/php4. There is also some query string as part of ...
8
votes
4answers
719 views

CAM table attack in 2011?

Today's switches are vulnerable to CAM Table attack? https://secure.wikimedia.org/wikipedia/en/wiki/CAM_Table
1
vote
3answers
180 views

Can man-in-the-middle attacks affect anyone not connected to the attackers network?

I'm trying to understand what these attacks are restricted to. I'm aware that man-in-the-middle attacks can be done if the attacker is on the same network (using something like Wire Shark), but is it ...
31
votes
4answers
7k views

Security of passphrase-protected private key

If an attacker obtains a private key that was created with no passphrase, he obviously gains access to everything protected with that key. How secure are private keys set up with a passphrase? If an ...
12
votes
6answers
5k views

Index page has been compromised, suspicious files are showing up

My website has been hacked lately and it has been defaced. Now I have weird files, don't know where they coming from. I just want to know, what of these files are harmful or can cause that I get ...
10
votes
2answers
2k views

Malware known to use port knocking to evade detection by network scanners?

Are there any known cases of malware in the wild that utilize port knocking on a backdoor to evade detection by network scanners?
7
votes
2answers
5k views

Need help identifying the OSX process that's generating strange network traffic

Since the past few days, I noticed that my router was a bit slow, and was restarting by itself at times. When looked at it's logs, they had entries like: Friday Jul 13 13:09:02 2012 1 Blocked by DoS ...
10
votes
2answers
1k views

Plain Text Password Reset Vulnerability

If I receive an email with a plain text generated password (in response to a password reset request), is this a vulnerability? The password expires after one use, in other words the user has to change ...
5
votes
2answers
5k views

Escalating from Apache shell to root

I have one noob question.I tried to exploit shellshock on my Slackware linux server, but after I connect with reverse shell and User Agent I get that I am apache user and apache user don't have too ...
3
votes
1answer
1k views

secure website against the ping of death attacks

Any programmer is interested in securing his website. So I found this http://www.youtube.com/watch?v=DB4eMFrQYiY&feature=youtube_gdata_player which talks about crashing a website using cmd only. ...
6
votes
2answers
2k views

Memory Dumping - Cause for concern in Virtualization?

Recently, I started exploring threats to Virtual machines in general. The first question that popped into my head was whether a host machine can dump its entire memory onto a file, and inspect the ...
2
votes
3answers
174 views

Feasibility of time-based database brute-force attacks on websites

I recently learned that there is an attack that utilizes the fact that when brute-forcing a compared string (e.g. hash from a password or token) in a database the query fails a few nanoseconds earlier ...
6
votes
4answers
2k views

VGA/HDMI Based Attack

Can I attack a PC via the VGA port? Is VGA one way or does it accept data from the other side? How about HDMI or DVI? And if so, are there known malware or PoCs to do that? or is it theoretically ...
4
votes
2answers
511 views

Are there volatile memory chips which dont retain data after power off?

It was demonstrated that dram modules can retain information up to 10 min after power off in certain conditions. My question - are there memory types which will retain data 10 sec at max even if being ...
3
votes
1answer
582 views

What are security risks of serving user uploaded files without Content-Disposition?

Imagine a server that serves untrusted user-provided files and allows other users to download them. Under some circumstances server can be tricked to return responses to download file requests without ...
2
votes
1answer
1k views

How does Binding Images with Malicious Patches happen?

Well I don't know if this technique is still used, but about 5-7 years ago it was a popular way to deliver a malicious patch (Sub-7 , bifrost etc ..) to a victim. There used to be a program that ...