Questions tagged [attacks]

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.

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160
votes
3answers
82k 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 ...
91
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4answers
18k views

How does XSS work? [closed]

I have very little experience in web development, but I'm interested in security. However, I haven't fully understood how XSS works. Can you explain it to med? The Wikipedia article give me a good ...
53
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4answers
22k 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 ...
246
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4answers
111k 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 is the ...
69
votes
1answer
43k 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?
16
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6answers
601 views

How are attacks and APTs attributed?

It's increasingly common to see major attacks on governments and corporations attributed to a specific country or group. Typically we don't know for certain, but it's at least suspected. Given the ...
45
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6answers
83k 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 ...
75
votes
19answers
6k views

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

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 tracks ...
109
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8answers
41k 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? ...
69
votes
3answers
144k 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 ...
73
votes
5answers
26k 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 preg_replace("\xf4\x30\41\x1f\x16\351\x42\x45"^"\xd7\30\xf\64\77\312\53\40","\373\x49\145\xa9\372\xc0\x72\...
92
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7answers
14k views

Script Kiddies - how do they find my server IP?

I've set up a site on Digital Ocean without a domain yet, so there is only the IP. Despite telling no-one of its existence or advertising it, I get hundreds of notices from fail2ban that various IP's ...
53
votes
7answers
72k 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 ...
14
votes
2answers
17k 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 ...
136
votes
8answers
22k 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 ...
176
votes
9answers
284k 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 ...
106
votes
5answers
19k views

Can simply decompressing a JPEG image trigger an exploit?

The novel Daemon is frequently praised for being realistic in its portrayal rather than just mashing buzzwords. However, this struck me as unrealistic: Gragg's e-mail contained a poisoned JPEG of ...
20
votes
3answers
22k 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 ...
16
votes
6answers
10k views

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

Can someone explain to me the concept of DoS attacks for web applications? Also, what is the distinction between DoS and Distributed DoS (i.e. DDoS) attacks? Wikipedia says: In computing, a denial-...
32
votes
3answers
6k views

How does one defend against software supply chain attacks?

In reference to the Solarwinds attack, since many organisations have no access to the source codes of the software vendors from whom they just consume the services, how can organisations defend ...
4
votes
1answer
3k views

SUID not used after exploit

I know the following When you execute a program that has the SUID bit enabled, you inherit the permissions of that program's owner. I am currently user1, but want to read the pass of user2 I ...
78
votes
7answers
52k views

SQL injection -- why isn't escape quotes safe anymore?

Raw SQL When you're writing SQL -- for anything that takes human input really, a lot of things have been done to avoid the injection. Everyone that's heard of SQL injection knows that (I'm going to ...
32
votes
3answers
12k 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. ...
27
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6answers
7k 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 ...
32
votes
20answers
7k 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 ...
25
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8answers
31k 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?
34
votes
3answers
3k views

Security implications of rooting Android

My Android smart phone has fancy features that I can get only if I root it, e.g., free-wifi tethering or Cisco VPN (with group name/password). However, the procedure to root my phone makes me ...
19
votes
1answer
6k 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 ...
20
votes
5answers
2k 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 ...
8
votes
1answer
8k views

What exactly is an evil maid attack?

Today I received the message below, after booting my PC: What exactly is an "Evil Maid"-attack? What are possible ways to get attacked by this? What does it mean in this case, that my disk "may have ...
7
votes
3answers
943 views

Are CSRF Attacks Really Blind

I'm new to CSRF attacks but don't see how they are always blind. Let's say we are dealing with a site where the asset we need to protect is the HTTP response. Something like one's medical history. ...
2
votes
2answers
10k views

How do traffic correlation attacks against Tor users work?

I was reading about how Tor works. There is says that if the attacker is able to see both ends of the communication channel then Tor fails (and other anonymous networks too). How and why does this ...
50
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5answers
10k 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, ...
67
votes
2answers
20k views

How can ISPs handle DDoS attacks?

How can an ISP with low bandwidth like 50 Gbps handle a DDoS attack with more than this? I know there is a solution called "Black Hole". Is this enough to mitigate DDoS attacks or are there any other ...
27
votes
5answers
9k 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 ...
14
votes
5answers
17k 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 ...
47
votes
4answers
18k 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 ...
22
votes
5answers
27k 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 -...
25
votes
4answers
8k 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 ...
13
votes
4answers
723 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
4answers
1k 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 ...
12
votes
2answers
3k 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 ...
8
votes
4answers
6k views

Can anti-CSRF token prevent bruteforce attack?

I am not much experienced with brute force attacks but I was wondering Suppose, you have a website www.example.com and you want to do brute force attack on that login form but that login form is ...
8
votes
3answers
5k 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 ...
13
votes
3answers
13k 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 ...
8
votes
4answers
943 views

CAM table attack in 2011?

Today's switches are vulnerable to CAM Table attack? https://secure.wikimedia.org/wikipedia/en/wiki/CAM_Table
5
votes
3answers
801 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 ...
2
votes
1answer
2k views

Should I be worried by an email which said my account was under attack? [duplicate]

So, today I received an email in my Gmail account which landed automatically in the spam folder. This was the email content: Hi! As you may have noticed, I sent you an email from your account. ...
2
votes
1answer
8k views

Is Diffie–Hellman key exchange protocol vulnerable to man in the middle attack?

Diffie–Hellman key exchange protocol vulnerable to man in the middle attack? If yes, then what type of MITM is that? I believe that is a replay attack or a relay attack, not sure though.
1
vote
3answers
1k 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 ...