GEN:SID 1:2671
Message WEB-CLIENT bitmap BitmapOffset integer overflow attempt
Summary This event is generated when an attempt is made to exploit a known
vulnerability in Microsoft Internet Explorer.
Impact A successful attack can cause a buffer overflow and present the attacker
with the opportunity to execute code of their choosing on a vulnerable
system.
Detailed Information An error in the processing of bitmap images exists in Internet Explorer
that can present an attacker with the opportunity to execute code of
their choosing on a vulnerable system.

The error exists due to poor boundary checking in the processing of
bitmap images.
Affected Systems Microsoft Windows using Internet Explorer
Attack Scenarios An attacker would need to supply a malformed bitmap image either in a
web page or possibly via HTML email to a victim host.
Ease of Attack Simple, exploits exist.
Corrective Action Upgrade to the latest non-affected version of the software.

Apply the appropriate vendor supplied patches.
Additional References Microsoft:
http://www.microsoft.com/technet/security/bulletin/ms04-025.mspx
Rule References bugtraq: 9663
cve: 2004-0566