prevention of an attack vector (e.g. XSS, HPP, CSRF)

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143
votes
12answers
26k views

How is an ATM secure?

I'm curious why an ATM computer is considered secure. The general adage of "If an attacker has physical access to my machine, all bets are off," seems to not apply in this circumstance (since ...
65
votes
13answers
13k views

Why do sites implement locking after 3 failed password attempts?

I know the reasoning behind not letting infinite password attempts -- brute force attempts is not a meatspace weakness, but a problem with computer security -- but where did they get the number 3 ...
61
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 ...
39
votes
6answers
11k views

What techniques do advanced firewalls use to protect againt DoS/DDoS?

It is hard to protect a server against Denial of Service attacks, DoS/DDoS. The two simple ways I can think of is to use a server with much resources (e.g. CPU and memory), and to build the server ...
38
votes
2answers
4k views

Is it good practice to ban an IP address if too many login attempts are made from it?

Since an IP address does not necessarily represent a specific device, but probably a whole network/company/etc. does it at all make sense to block an IP address if there is a significant amount of ...
33
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? ...
30
votes
7answers
2k views

Is there a difference between GET and POST for web application security?

I have 2 choices in sending data between 2 web applications. I encode the data in Base64 and append to the URL and retrieve these parameters at my destination application and decode the parameters. ...
25
votes
6answers
368 views

User input data, is filtering enough or should it be parsed?

In a webapplication there could be two approaches to migate XSS attacks. All the input data could be filtered (removing all 'bad' data), or the input could be parsed, tokenized and output with only ...
24
votes
2answers
2k views

How can a Software application defend against DoS or DDoS?

Most of the solutions for DoS attacks are not at the application level. In case I am using a proxy server, what are the possible countermeasures for DoS at the application level?
22
votes
3answers
2k views

Does overlaying the mouse on a virtual numeric keyboard really protect against keyloggers?

I just saw for the first time a new way to enter a password, at the Banque Postale (French Bank). You are given a virtual numeric keyboard and to type you can just leave the mouse cursor over a number ...
20
votes
7answers
826 views

How can I protect a WordPress installation?

How do you go about protecting a default WordPress installation? What checklist do you use, best practices, tips and tricks, etc? Any recommendations on plugins, third-party tools are welcome.
19
votes
5answers
2k views

Should I let a user know they have entered an unknown username or email address?

On my website I have a password reset page that users can use if they have forgotten their password. On this page they can enter their username or their email address and hit "reset" which will send ...
19
votes
2answers
621 views

How is “<scrscriptipt>” or “selselectect” used to avoid filtering?

A technique for avoid filtering of common words is the one I described in the title. However, why does this technique work? SELECT isn't the same as SELSELECTECT for example.
19
votes
5answers
1k views

Designing in zero day attack mitigations

What are best practices / recommendations / strategies for mitigating zero day threats/attacks from a software development perspective?
19
votes
8answers
3k views

How could someone exploit the OS an ATM is running?

As I'm sure many of you have heard, the end of support for Windows XP is the supposed apocalypse for ATM's worldwide. I am cognizant of the fact that this ensures that no more patches are issued, and ...
18
votes
8answers
1k views

Ways to secure yourself from Firesheep kiddies and other sniffing

Just a few days ago I had my first encounter with Firesheep. Luckily I was the one using it. Well, it scared me into looking for ways to secure myself. So I have two questions: In exactly what ...
18
votes
5answers
1k views

Can you secure a web app from FireSheep without using SSL?

Assume that you want to give some web users privileged access to your website, but that you are unable (or unwilling) to offer SSL to all of them - at least past the initial login page. In this ...
18
votes
3answers
5k views

DNS Amplification DDOS attack

During the weekend I made some tests to simulate an DNS Amplification DDOS attack. sending about 90Mb/s traffic I was able to generate about x.x Gb/s amplified traffic which sent our datacenter ...
17
votes
3answers
9k views

Is there a way to mitigate BEAST without disabling AES completely?

It seems that the easiest way to protect users against the BEAST attack on TLS <= 1.0 is to prefer RC4 or even disable all other (CBC) cipher suites altogether, e.g. by specifying something like ...
17
votes
2answers
10k views

Should I disable SSL compression because of CRIME?

I've read CRIME - How to beat the BEAST successor? and a few articles on the subject (linked below) and found no recommendations for system administrators. As a web host, should I disable SSL ...
17
votes
3answers
1k views

Rails - protection against code injection and XSS

I've started using Ruby on Rails, and I was wondering if there were any security gotchas to watch out for with Rails, particularly regarding code injection and XSS? I know Rails tries to prevent ...
16
votes
4answers
8k views

What is the correct way to implement anti-CSRF form tokens?

I am fully aware of CSRF and have already implemented some safe forms, but I have never been happy with the results yet. I've created tokens as a md5 of username, form info and a salt and stored it ...
16
votes
7answers
4k views

Any comprehensive solutions for binary code protection and anti-reverse-engineering? [closed]

Does anyone know of good products with comprehensive binary hardening and anti-reverse-engineering features? Or better, has anyone seen an independent review comparing products that perform these ...
16
votes
3answers
2k views

What steps should be taken to validate user uploaded images within an application?

Recently I have worked on a number of applications that need to process user uploaded images steps have been taken to validate the extension and the mime type. But what else can be done to ensure ...
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 ...
13
votes
4answers
574 views

How to protect off-the-shelf web applications?

As an exercise, please consider the following: If you are faced with having to deploy off-the-shelf web applications that you are unsure about the vendors security coding practices, which techniques ...
13
votes
9answers
606 views

What do you see as the emerging threats for 2011

As we move in to the new year, what do you see as the emerging threats for organisational security? I see more chat around; Advanced Persistent Threat (APT) from foreign states. More fines from the ...
13
votes
6answers
4k views

Why is ARP poisoning killing all network activity?

Using ettercap and ARP poisoning, I was able to eavesdrop on other connections, but suddenly I was unable to make any connection to the Internet. To restore Internet connectivity, I had to restart my ...
13
votes
3answers
586 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 ...
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
2answers
286 views

Why do browsers allow public websites to attack intranet sites?

When I'm visiting a website on the public internet, the website can cause my browser to send requests to a local IP address (such as 10.0.0.1). This can be used to attack internal web sites, e.g., ...
12
votes
2answers
430 views

Detecting website attack attempts

I am currently trying to implement some recommendations from OWASP AppSensor Project and I'd like to respond to attacker, when he tries to break into my website. Is there any resource ...
11
votes
5answers
3k views

QR codes that can't be copied - possible?

I assume this is impossible, but I need to find a barcode (that can contain a url, i.e., a QR style one). It has to be photographed by our smartphone app, but the image will not be changed over a ...
11
votes
8answers
2k views

Can malware be attached to an image?

I have a small number of employees who use a company computer but these people aren't very tech savvy. They use an email client and a messaging client. I'm pretty sure they wouldn't click on .exe or ...
11
votes
3answers
3k views

How can I prevent someone from accessing a Windows XP system via boot disk?

Apparently a computer system protected by a a login password, e.g. Windows XP, can be easily hacked by someone with physical access to it using methods like this one: ...
11
votes
6answers
3k views

How can mini-computers (like Raspberry Pi) be applied to IT security?

It's no secret that thousands of $35 Raspberry Pi (Model B) computers have just shipped to people around the world. With these, and other similar types of computers becoming cheaper and more ...
11
votes
5answers
599 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
3answers
291 views

What are the pros/cons of using a threat detection system?

What are the pros/cons of using a threat detection system for a web app (like OWASP's AppSensor)? What does a properly implemented threat detection system do and how does it behave when it detects ...
11
votes
4answers
437 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 ...
10
votes
7answers
1k views

Whitelisting DOM elements to defeat XSS

As we know, developers are responsible for correctly escaping/validating data provided by the user before rendering or storing them. However, we must agree that it's relatively easy to forget a single ...
10
votes
6answers
382 views

Should we configure all devices to never request SSL 2.0, and reject it if offered?

In an effort to reduce man in the middle attacks, when will it be (or was it) an industry accepted practice to reject SSL 2.0 connections on the client and server side? Is configuring this on a proxy ...
10
votes
2answers
302 views

How do you compare risks from your websites, physical perimeter, staff etc

In assigning budget rationally - ie proportionally to the risk in a particular area, how can you calculate the relative risks? I can think of examples where clients of mine have secured their ...
10
votes
2answers
3k views

How to address XSS security issues in FCKeditor / CKeditor?

A security report we conducted through an outside company reported XSS vulnerabilities in FCKeditor which we're using in our PHP application. They pointed out that accessing URLs such as: ...
10
votes
3answers
1k views

Securing a laptop against attacks (article)

I came across this article when looking for ways of hardening my laptop, and this guide seemed extremely thorough. It is perhaps overly paranoid, but it will be good to have a guide I can trust should ...
10
votes
7answers
632 views

IP address black list

My website has a black list of IP addresses. The web application, in some way, detects all invalid, suspicious influences to it and remembers IP address and denies any requests from that IP address. ...
10
votes
3answers
1k views

Possible to prevent Juice Jacking by only connecting USB pins 1 & 4?

According to this accepted answer, there is no phone on the market today that is immune from "Juice Jacking"*. I think an easy way to mitigate this threat is to have a filter that blocks USB pins 2 ...
10
votes
2answers
908 views

Interpolique: transparently preventing SQL Injection and XSS with base64 encoding, what happened?

For the keynote at The Next HOPE a couple of years ago, Dan Kaminsky unveiled Interpolique (the talk is really fun btw). The problem he raised was how to defend against injection attacks, including ...
9
votes
1answer
3k views

SSL replay attack when client/server random is missing

Hey studying the SSL protocol, I'm wondering how can someone be able to do a replay attack if the server nonce is missing? All the material I find says that nonces prevent it, but theres no examples ...
9
votes
3answers
687 views

Is it possible to prevent a physical attack on full disk encryption?

I've been researching into some methods to ensure that disk encryption keys can't be stolen, and one that I've come across is called TRESOR. With this kernel patch, you can create a partition that is ...
9
votes
2answers
187 views

Should I prevent user from operating with site during some first seconds?

Imagine the following scenario: User is at attacker.com and plays a game there. Just before he clicks at some point he is rerouted to victim.com using browser's history. User thought that he clicked ...