Questions tagged [xss]

Cross-Site Scripting: An attack method that involves injection of code or markup into a webpage. There are three major types of XSS: Reflected XSS, Stored XSS (aka persistent XSS) and DOM-based XSS (aka client side XSS).

Filter by
Sorted by
Tagged with
7
votes
2answers
298 views

Presentation on Web App Security (ACM Student Chapter)

I am a member of the local ACM student chapter in my university and as part of our activities I am scheduled to give a talk on current issues on Web Application Security (and possibly secure coding ...
24
votes
6answers
6k views

Filter user input before the database or upon display?

Given a web application where user data must be properly escaped to avoid XSS, is it better to try to remove the "bad stuff" before it enters the database, or is it best to allow it in the database ...
3
votes
2answers
6k views

Is there a way to bypass escape function in javascript?

Is there a way to bypass escape function in javascript for exploiting a XSS vulnerability ?
12
votes
1answer
3k views

Closing an HTML element without using literal slashes?

I'm investigating a vulnerability in an application that echoes a user-supplied filename without sanitizing the filename. E.g. a file named test-<script>alert("evil");.txt will result in that ...
6
votes
4answers
2k views

Server wide javascript injection

UPDATE: The server was rooted, php.ini was replaced that cause the injection to appear. Still haven't figured out which directive is injecting the javascript. I'm troubleshooting a hacked website ...
22
votes
1answer
6k views

Does the practice of blocking an off-site “Referer:” HTTP requests improve website security?

Is there any benefit for a security-paranoid website to disallow HTTP requests that have a Referer: from 3rd party sites? The pitch is that if such a HTTP request were to come in, then certain XSS ...
15
votes
3answers
6k views

How serious are XSS attacks

A website I visit allows this kind of attack, to be implemented with GET in the URL <SCRIPT SRC=http://ha.ckers.org/xss.js></SCRIPT> Along with many others on this page: http://ha.ckers....
3
votes
1answer
437 views

Has The IE8 XSS Filter XSS Flaw Been Fixed?

You may remember: X-XSS-Protection: 0 http://hackademix.net/2009/11/21/ies-xss-filter-creates-xss-vulnerabilities/ Has this been fixed in IE8? IE9? IE10? Is it implemented in IE7?
3
votes
5answers
1k views

Is it possible to see if a script on a website steals session cookies?

I'm looking as some web analytics solutions, I know it sounds paranoid. but cookie-based web analytics need for you to paste their JavaScript code on your web-site. I don't like the idea too much of ...
5
votes
2answers
4k views

Are PHP Sessions based on cookies or a cookie-IP pair?

I have a PHP website and my question is: If someone manages to steal my users' cookies via an XSS attack, is it enough for him to be identified as the user? Or does his IP also have to be the same as ...
11
votes
2answers
6k 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: http://www....
7
votes
4answers
847 views

Is XSS dangerous in application without database?

I think it definitelly isn't, because XSS which isn't saved anywhere would damage ONLY attacker. Am I right or are there any cases where XSS could hurt non-db-application? (I mean datas are not saved ...
4
votes
2answers
3k views

How to protect from new Javascript Injection technique that doesn't use eval()?

There is a new Javascript injection technique that is generating chatter on the forums mentioned here Here is the code sample: String.prototype.code = function(){ return (new Function('with(this) { ...
10
votes
2answers
771 views

Recent Facebook XSS exploit details

There was a recent XSS exploit on Facebook that posted a vulgar message and got users to click on a link to spread the payload. What vulnerability was exploited, and what can other sites do to avoid a ...
18
votes
4answers
2k views

Web Security Cheatsheet / ToDo list

Can anyone suggest a cheatsheet or ToDo list of web site and application security? A local small business owner prompted a question about web security, basically her company website just got XSS ...
6
votes
3answers
541 views

Is Content Security Policy an approach that is worth to support?

Mozilla Firefox 4.0 supports something called Content Security Policy that disables the interpretation of embedded Java Script. Only external Java Script files that are referenced using a script tag ...
4
votes
3answers
4k views

Altering a $_SESSION variable in PHP via XSS?

Not sure if what I'm saying makes sense... but is it possible for me to alter a $_SESSION variable from outside the target PHP script? One of our scripts uses a $_SESSION variable and I'm not sure if ...
1
vote
1answer
264 views

Replicating javascript actions from different website (XSS?)

I've got html / javascript code on my site like this: <a onclick="validateForm('formEdit',...,'submitpage(&quot;mypaymentsettings&quot;,&quot;320&quot;)','show_confirmation_message(...
2
votes
2answers
466 views

Protecting websites from outdated browsers and plugins via a whitelist/blacklist combination?

Aside from using browser headers, I want to blacklist/whitelist browser and plugins from my site so that I can prevent these older unpatched systems from (1) being a general user of my site (2) ...