VRT Advisories


VRT Rules 2005-11-22

Sourcefire VRT Advisory

Date: 2005-11-22

Synopsis:

The Sourcefire Vulnerability Research Team (VRT) has learned of the release of proof of concept code that demonstrates the ability to execute code via a vulnerability in the way that Internet Explorer handles a Javascript event.

The Sourcefire VRT has confirmed that a rule identified as sid 4647, released on November 9, 2005, will generate events when an attempt is made to exploit this vulnerability, including the use of the proof of concept code.

Details:

A vulnerability exists in the way Internet Explorer handles the window() function supplied to the javascript "onload" handler as a parameter. The conditions for exploitation occur when a page is opened in the browser that uses <body onload=window();>.

Detection:

Sourcefire rule packs released on November 9, 2005 contained sid 4647 that will generate events when an attempt is made to exploit this vulnerability, including the use of the proof of concept code.

Note: Sid 4647 is NOT enabled by default. Should detection for this vulnerability be needed, this rule should be enabled.

Additional References:

Microsoft Security Advisory (911302)
http://www.microsoft.com/technet/security/advisory/911302.mspx

About the VRT:

The Sourcefire VRT is a group of leading edge intrusion detection and prevention experts working to proactively discover, assess and respond to the latest trends in hacking activity, intrusion attempts and vulnerabilities. This team is also supported by the vast resources of the open source Snort community, making it the largest group dedicated to advances in network security industry.