Software Engineering Institute

Symantec Security Advisory SYM12-007 states:

Overview
Versions of Symantec Endpoint Protection Manager 11.0 running the Network Threat Protection module on Windows Server 2003 are susceptible to a Denial of Service(DoS). Successful exploitation could potentially result in the system hosting Symantec Endpoint Protection Manager becoming unresponsive to IIS-based web server requests until restarted.

Details
Symantec was notified of a Denial of Service(DoS) within the Symantec Endpoint Protection Manager 11 RU6 and related maintenance packs.

A successful exploitation is possible when using audit tools to aggressively scan the targeted Symantec Endpoint Protection Manager host. After a period of heavy scanning the Network Threat Protection module responds to the perceived threat by blocking all subsequent traffic to the server. This can lead the server to stop serving pages and in some instances can cause excessive resource use which can lead to a hang or crash of the server.

This issue does not impact the security of the Symantec Endpoint Manager, only the availability of the web server components.

It has been reported that this vulnerability affects Microsoft Internet Information Services (IIS) 6.0, however newer versions could be affected.

An unauthenticated attacker can cause the Microsoft IIS webserver to become unresponsive leading to a denial of service condition.

Update

The vendor has stated that this vulnerability has been addressed in SEP 11.0.7000 RU7 MP2. Users are advised to upgrade to release SEP 11.0.7000 RU7 MP2 or later. The vendor states that updates will be available through customers’ normal support/download locations.

Restart server or IIS service

The vendor has stated that manually restarting the server and/or IIS service will remedy the situation.