Cross-site scripting request forgeries

Attack of the CSRF

Article from Issue 99/2009
Author(s):

Sometimes, even ING, YouTube, The New York Times, and Google get it wrong.

Cross-Site Request Forgery (also referred to as Cross-Site Reference Forgery, CSRF and XSRF) is  apidly becoming a serious security problem of which most programmers and users are blissfully unaware. CSRF is a web-based attack that has grown out of, and remains a close cousin to, the more traditional Cross-Site Scripting (XSS) attacks. In an XSS exploit, the attacker inputs malicious content into a web application (e.g., by creating a malformed URL or embedding hostile code in a response box) that results in hostile content such as JavaScript being inserted into otherwise safe content that then is served to the victim. CSRF attacks take it a step further by inserting hostile content that results in an action by the user's web browser, such as changing a filter setting within web-based email or initiating a money transfer from an online bank account.

A CSRF Attack Example

So you go to your favorite social networking site to chat with friends. Unfortunately, the site in question allows users to insert images into web-based conversations (e.g., avatars for a forum). Instead of using a URL such as:

<img src="http://random-site/ image.jpg">

[...]

Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
 
SUBSCRIPTIONS
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

Learn More

News