VRT Advisories

VRT Rules 2009-09-01

Sourcefire VRT Rules Update

Date: 2009-09-01


This release adds and modifies rules in several categories.


Microsoft IIS FTP Buffer Overflow: The Microsoft FTP module for Internet Information Services (IIS) contains a programming error that may allow a remote attacker to execute code on an affected system. The problem occurs in the processing of specially crafted directory names which an attacker can leverage to cause a stack-based buffer overflow.

Previously released rules will detect attacks targeting this vulnerability and are identified with GID 1, SIDs 1529, 1973, 2374 and 3441. Additionally, the FTP Telnet preprocessor will detect attacks targeting this vulnerability. These events are identified with GID 125, SIDs 3, 6 and 8.

Additionally, as a result of ongoing research, the Sourcefire VRT has added multiple rules to the web-activex, web-client, specific-threats, shellcode and bad-traffic rule sets to provide coverage for emerging threats from these technologies.

Rule Pack Summary:

For a complete list of new and modified rules, click here.


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.