An attempt by a threat to exploit a weakness in a system.

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109
votes
8answers
11k views

Are “man in the middle” attacks extremely rare?

In http://cdixon.org/2012/02/12/the-iphone-contact-list-controversy-and-app-security/ Chris Dixon makes a statement about web security Many commentators have suggested that a primary security ...
75
votes
8answers
77k views

Can webcams be turned on without the indicator light?

I want to know how secure I am. I've made a series of pentests 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 ...
74
votes
8answers
7k views

How would one crack a weak but unknown encryption protocol?

I was reading this interesting question: Is my developer's home-brew password security right or wrong, and why? It shows a weak home-brew algorithm developed by "Dave", and the answers discuss ...
62
votes
2answers
10k 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 ...
60
votes
6answers
7k 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 ...
57
votes
18answers
3k 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 ...
52
votes
8answers
81k 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 ...
49
votes
6answers
11k views

SQL injection — but why isn't escape quotes safe anymore?

I haven't seen this question asked, and feel it's a valuable bit of information to have, especially because this is a huge source of mystery and confusion. Raw SQL When you're writing SQL -- for ...
39
votes
5answers
4k views

New XSS cheatsheet?

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, ...
34
votes
8answers
3k views

Should I bother teaching buffer overflows any more?

The students are skeptical that turning off non-executable stacks, turning off canaries and turning off ASLR represents a realistic environment. If PaX, DEP, W^X, etc., are effective at stopping ...
34
votes
4answers
4k 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? ...
28
votes
20answers
3k 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 ...
26
votes
3answers
1k views

How can an attacker use a leaked private key?

I admit that while I'm a programmer, my crypto/security knowledge is fairly basic. I understand that the potential of leaking private SSL keys is cited as one of the most serious effects of the ...
22
votes
3answers
3k 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. ...
22
votes
8answers
9k views

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

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?
21
votes
1answer
1k views

Security implications of rooting your android phone

My android smart phone has fancy features that I can get if and only if I root it, e.g., free-wifi tethering or Cisco VPN (with group name/password). However, the procedure to root my phone has me ...
19
votes
4answers
3k 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 ...
18
votes
7answers
815 views

Are common passwords at particular risk?

The question Should we disallow common passwords like “password” and “12345”? on User Experience immediately made me think that these common passwords were extremely dangerous not because they are ...
18
votes
2answers
2k views

How can vending machines be hacked? And how can I prevent it?

I am developing a vending machine and want to make it secure. In a comment to my previous question, @Polynomial said "Vending machines (and similar devices) can often be pwned via buffer overflows on ...
18
votes
4answers
4k 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 ...
18
votes
1answer
2k 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 ...
18
votes
2answers
813 views

A phone call hack

The other day, I got a call from a relative with an email problem. After a bit more discussion, it turns out that two days previously, a man phoned my relative: stated he was from microsoft; asked ...
18
votes
2answers
11k 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 ...
17
votes
5answers
10k 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 ...
16
votes
5answers
14k 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 ...
16
votes
4answers
1k views

What is the easiest way to search massive, leaked databases for persons and personal information?

This may seem like a rather nefarious question, however, my motivations are quite the opposite-- I want to know how at risk I might be! A while ago a very MASSIVE database was leaked that contained ...
16
votes
5answers
1k views

Rainbow table concept for Prime numbers

Is there a concept where pre-computed tables can be used for prime number factorization ? Is it possible that a computer can generate millions of prime numbers, store it and then effectively determine ...
16
votes
6answers
1k 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 ...
16
votes
4answers
1k views

Security risks of scanning an unknown QR code

What are the security risks of scanning a QR code from an untrusted source? If the QR code was constructed by an attacker, what can the attacker do to me? Do widely used QR scanners have any known ...
15
votes
3answers
1k views

NTP DDoS Attack on Home Servers

After some half-good script kiddies found out about this exploit or DDoS method, they have been doing it like crazy to websites, game servers, and now my home servers which allows me to work on some ...
15
votes
5answers
13k 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 ...
14
votes
4answers
303 views

What should I look at in the event of a major vendor suffering compromise with unspecified impact?

The specific example I have in mind here is the breach of RSA in March 2011 where attackers got away with critical information which could be the seed information which is used to generate the ...
14
votes
3answers
593 views

What prevents people getting charged over NFC in crowded places?

I don't have an NFC-enabled device and I couldn't find any information about this in Google. What is it that protects me against an attacker with a portable NFC terminal charging payments by just ...
14
votes
2answers
507 views

Does it make sense to hash a session id before passing it to an advertisement partner?

My company runs a webshop. We work with a partner that gives discount vouchers to our customers after they buy (the vouchers can be used in other online shops) and also gives vouchers for our shop to ...
13
votes
5answers
2k 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 ...
13
votes
2answers
356 views

Concrete figures on password cracking in the wild

While password guessing is a science, not every attacker out there is up-to-date with the latest advances or cares to invest in GPUs or FPGAs. It's easy enough to test online password guessing ...
12
votes
8answers
1k views

Randomizing MAC addresses on bootup

Since it is possible to set custom MAC addresses, wouldn't it make sense to have a new one as often as possible/convenient (i.e. on bootup)? It would seem that is useful to both attacker and victim ...
12
votes
7answers
420 views

UNIX Servers: Possible intrusions or attacks that do not use any of the open listen sockets

What type of attacks are there that do not use open TCP or open UDP ports? Is it safe to assume that no open ports means no remote access? (Excluding the possibility that there is a badware already ...
12
votes
5answers
4k 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 ...
12
votes
3answers
1k views

Bypassing Address Space Layout Randomization

How effective is ASLR in preventing arbitrary code execution in a buffer overflow type exploit? How hard is it for an attacker to bypass this without simply guessing where the addresses are?
12
votes
1answer
969 views

How to make a report after a ddos attack? what information do I need to write on the report?

In my company, after a DDOS against a server, my employer asked me to make an analysis of the attack and to write down some stuff. What do you think I need to write down in my report? Is there any ...
12
votes
1answer
5k 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?
11
votes
7answers
2k views

Can hackers detect my operating system?

I've seen people demonstrating the use of backtrack to attack VMs. In one of the components of backtrack, it shows the operating system of the targets. Since support for Windows XP is ending soon, i ...
11
votes
8answers
11k views

Is it possible to steal money directly from the systems of a big bank?

Sometimes I imagine: My money in the bank is just a floating point number in a mainframe's memory... So, if I just change 1 bit, I will win a lot of money... The most common way to steal money in ...
11
votes
5answers
3k 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 ...
11
votes
5answers
627 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 ...
11
votes
2answers
1k views

Is null-byte injection possible in Java filenames?

From the Area51 proposal
11
votes
4answers
640 views

What is the risk of a packet being sniffed when travelling over the internet without SSL/TLS?

We all know to use SSL/TLS to stop people eavesdropping on our connection, but how likely is it that an attacker will actually sniff your unencrypted password or cookie if you don't? If we exclude ...
11
votes
2answers
243 views

security implications of NULL dereference

Suppose we have code like this: struct somedata { int a; int b; }; struct somedata *data; /* ... */ data = malloc(sizeof(struct somedata)); data->a = something; Now, as you can see, NULL ...
11
votes
4answers
463 views

How to react when under attack

Just this week someone has been trying to attack the server of the company where I work. I have noticed that they have been trying to brute force root via ssh. fail2ban is handling that well and I ...