What is Cross Site Scripting?
Cross site scripting (also known as XSS) occurs when a web application gathers malicious data from a user. The data is usually gathered in the form of a hyperlink which contains malicious content within it. The user will most likely click on this link from another website, instant message, or simply just reading a web board or email message. Usually the attacker will encode the malicious portion of the link to the site in HEX (or other encoding methods) so the request is less suspicious looking to the user when clicked on. After the data is collected by the web application, it creates an output page for the user containing the malicious data that was originally sent to it, but in a manner to make it appear as valid content from the website. Many popular guestbook and forum programs allow users to submit posts with html and javascript embedded in them. If for example I was logged in as “john” and read a message by “joe” that contained malicious javascript in it, then it may be possible
Cross Site scripting (XSS) is a type of attack that can be carried out to steal sensitive information belonging to the users of a web site. This relies on the server reflecting back user input without checking for embedded javascript. This can be used to steal cookies and session IDs. Let’s see how it works. We would all have come across the following situation sometime – we type a URL in the browser, say www.abcd.com/mypage.asp, and receive an error page that says “Sorry www.abcd.com/mypage.asp does not exist” or a page with a similar message. In other words, pages that display the user input back on the browser. Pages like this could be exploited using XSS. Instead of a normal input, think what will happen if the input contains a script in it. While reflecting back the input, instead of rendering it as normal HTML output, the browser treats it as a script and executes it. This script could contain some malicious code. The attackers can send a link that contains a script as part of th
Cross-site scripting (also known as XSS) occurs when a web application gathers malicious data from a user. The data is usually gathered in the form of a hyperlink that contains malicious content within it. The user will most likely click on this link from another website, web board, email, or from an instant message. Usually the attacker will encode the malicious portion of the link to the site in HEX (or other encoding methods) so the request is less suspicious looking to the user when clicked on. After the data is collected by the web application, it creates an output page for the user containing the malicious data that was originally sent to it, but in a manner to make it appear as valid content from the website.
