“CrossSite Scripting (XSS) attacks are a type of injection problem, in which malicious scripts are injected into the otherwise benign and trusted web sites. Cross-site scripting (XSS) attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user. Flaws that allow these attacks to succeed are quite widespread and occur anywhere a web application uses input from a user in the output it generates without validating or encoding it.
An attacker can use XSS to send a malicious script to an unsuspecting user. The end user’s browser has no way to know that the script should not be trusted, and will execute the script. Because it thinks the script came from a trusted source, the malicious script can access any cookies, session tokens, or other sensitive information retained by your browser and used with that site. These scripts can even rewrite the content of the HTML page.” – OWASP
Understanding XSS or to make one understand it ain’t easy. Too much of theory will confuse the person rather than helping him out. The best way of explaining it!; through flash animations and that is how virtualforge guys have done. This animation is intended for both a layman and a security analyst.
They have published two set of flash applications which demonstrates XSS. Here cookie theft and file access are demonstrated.
Screenshot
Check the following links
Example 1 : Car Auction
http://www.virtualforge.de/vmovie/xss_lesson_1/xss_selling_platform_v1.0.swf
Example 2 : Online Application
http://www.virtualforge.de/vmovie/xss_lesson_2/xss_selling_platform_v2.0.swf
Read More about XSS at Wiki and OWASP
See CrossSiteRequestForgery (XSRF) in action, here.
