Rule:

--
Sid:
16573

--
Summary:
This event is generated when an attempt is made to exploit a known vulnerability in an ActiveX control.

--
Impact:
A successful attack can cause a buffer overflow and the subsequent execution of arbitrary code with system level privileges on a vulnerable host.

--
Detailed Information:
A vulnerability exists in the way that Internet Explorer handles ActiveX controls that may present an attacker with the opportunity to run code of their choosing on a host.

In particular, this event is generated when a call to an ActiveX object instantiation via unescape is made in an attempt to evade detection. This may indicate an attempt to exploit known vulnerabilities in that ActiveX control which may lead to a system compromise.

NOTE: For this detection to work comprehensively, the flow depth setting in the HTTP Inspect preprocessor must be set to 0

--
Affected Systems:
Microsoft Windows systems using ActiveX controls

--
Attack Scenarios:
An attacker can host a web site that will return code of their choosing to the object when a victim clicks on a malicious link.

--
Ease of Attack:
Simple.

--
False Positives:
None known.

--
False Negatives:
None known.

--
Corrective Action:
Upgrade to the most current non-affected version of the product.

--
Contributors:
Sourcefire Vulnerability Research Team
Alex Kirk <akirk@sourcefire.com>
Nigel Houghton <nigel.houghton@sourcefire.com>

--
Additional References

--
