VRT Advisories

VRT Rules 2005-11-17

Sourcefire VRT Certified Rules Advisory

Date: 2005-11-17


The Sourcefire Vulnerability Research Team (VRT) has learned of a vulnerability in the Microsoft implementation of RPC (MSRPC) that may allow an attacker to perform a Denial of Service (DoS) attack on an affected platform.

The Sourcefire VRT has confirmed that a rule identified as sid 4324, released on October 12, 2005, will generate events when an attempt is made to exploit this vulnerability via the UPnP service.


A vulnerability exists in the Microsoft RPC system that may present a remote attacker with the opportunity to cause a DoS condition on an affected host.

The condition is manifest when a malformed request is made to the UPnP service in the data section of a call to the GetDeviceList function. On processing this request, memory consumption increases to the point where the system becomes unresponsive, repeated requests of this nature will cause the DoS to occur.

Detection: Sourcefire SEU 5 and rule packs 30 and 40 released on October 12, 2005 contained sid 4324 that will generate events when an attempt is made to cause the DoS via the UPnP service.

Additional References:



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 network security industry.