A few weeks ago news broke of more listing containing cross scripting malicious code, this was widely reported (BBC, Tamebay articles) and caused some concern for a number of ebay sellers. We spoke with several of our own clients to reassure them regarding active content in their listings.
What is cross site scripting ?
Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into otherwise benign and trusted web sites. 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 within 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 the browser and used with that site. These scripts can even rewrite the content of the HTML page. For more details on the different types of XSS flaws
Source Wiki Cross Scripting XSS
What happened with the ebay attacks?
Users who clicked on one of the affected listings were being redirected to a spoof copy of ebay, when a user signed in their account details the person/s operating the spoof of the site would have all of their ebay user and password details. The affected listings belonged to real ebay account owners who own details had been compromised, criminals prefer to use a real account to post these infected listings as it makes the listing look all the more real and genuine.
What are ebay doing about the problem?
ebay today made an official annoucement regarding the issue via its General announcements section of ebay.com read the post here
The general theme of the announcement is that ebay has checked its security procedures and is happy that any risk posed from malicous listings is not enough to go and full scale ban the use of active content in item listings. By active content we mean javascript, flash, links, images etc, all of these content types serve to offer a better experience when browsing ebay. Many of the worlds best web sites use the exact same technologies to display their content, infact it is these content types that have helped shaped the web into the rich experience we now see today.
