VRT Advisories

VRT Rules 2007-05-16

Sourcefire VRT Advisory

Date: 2007-05-16


The Sourcefire VRT is aware of a technique that may be used in an attempt to bypass detection by IDS and IPS devices.


HTTP content scanning systems Unicode encoding bypass (VU#739224). US-CERT has issued a vulnerability note describing a technique that may be used in an attempt to evade detection by IDS and IPS devices.

For more information see http://www.kb.cert.org/vuls/id/739224

Sourcefire customers with SEU 76 or later installed are not affected by this evasion technique.


Sourcefire VRT rule packs often utilize enhancements made to Snort. Operators should upgrade to the latest revision or patch level for Snort to ensure these enhancements are available before using these rules.

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 the network security industry.