Skip to main content

Posts

Showing posts from January 5, 2012

Cross Site Scripting - XSS - The Underestimated Exploit

1. What is Cross Site Scripting? Cross Site Scripting  (or XSS) is one of the most common application-layer web attacks. XSS commonly targets scripts embedded in a page which are executed on the client-side (in the user’s web browser) rather than on the server-side. XSS in itself is a threat which is brought about by the internet security weaknesses of client-side scripting languages, with HTML and JavaScript (others being VBScript, ActiveX, HTML, or Flash) as the prime culprits for this exploit. The concept of XSS is to manipulate client-side scripts of a web application to execute in the manner desired by the malicious user. Such a manipulation can embed a script in a page which can be executed every time the page is loaded, or whenever an associated event is performed.

Preventing XSS Attacks

Cross Site Scripting (XSS) attacks are amongst the most common types of attacks against web applications. XSS attacks all fall under the same category however a more detailed look at the techniques employed during XSS operations reveals a multitude of tactics that exploit a variety of attack vectors. A detailed look at XSS attacks can be found in the following article;  Cross-Site Scripting attack . This article guides you through the most common and useful XSS prevention mechanisms which are Filtering and Escaping. XSS ATTACKS

Cross Site Scripting Attack

What is Cross Site Scripting? Hackers are constantly experimenting with a wide repertoire of hacking techniques to compromise websites and web applications and make off with a treasure trove of sensitive data including credit card numbers, social security numbers and even medical records. Cross Site Scripting (also known as  XSS  or CSS) is generally believed to be one of the most common application layer hacking techniques. In the pie-chart below, created by the Web Hacking Incident Database for 2011 (WHID) clearly shows that whilst many different attack methods exist, SQL injection and XSS are the most popular. To add to this, many other attack methods, such as Information Disclosures, Content Spoofing and Stolen Credentials could all be side-effects of an XSS attack.