Rule: 

--
Sid: 
3553

-- 
Summary: 
This event is generated when an attempt is made to exploit a known
vulnerability in the Microsoft Internet Explorer DHTML Engine.

-- 
Impact: 
Serious. Code execution may be possible.

--
Detailed Information:
Dynamic HTML extends static HTML pages to allow interactive web pages to
be easily created. A flaw in the Microsoft Internet Explorer DHTML
Engine may allow an attacker to exploit a race condition and possibly
execute code of their choosing on the victim host with the privileges of
the user running Internet Explorer.

Internet Explorer allows various DHTML objects to be used via
Javascript. Poor memory management in the object handling code of
Internet Explorer may allow an attacker to overwrite portions of memory
and execute code of their choosing on a vulnerable host.

--
Affected Systems:
	Internet Explorer 6

--
Attack Scenarios: 
An attacker need only supply the victim host with malicious Javascript
that calls on a vulnerable routine to cause the error to occur.

-- 
Ease of Attack: 
Difficult.

-- 
False Positives:
Some activity relating to the use of web applications may cause this
rule to generate events. Most public exploits will however, use this
particular selection of Unicode NOPs.

--
False Negatives:
None known.

-- 
Corrective Action: 
Apply the appropriate vendor supplied patch

Upgrade to the latest non-affected version of the software.

--
Contributors:
Sourcefire Vulnerability Research Team
Alex Kirk <alex.kirk@sourcefire.com>
Brian Caswell <bmc@sourcefire.com>
Nigel Houghton <nigel.houghton@sourcefire.com>

-- 
Additional References:

US-CERT:
http://www.kb.cert.org/vuls/id/774338

iDefense:
http://www.idefense.com/application/poi/display?id=228&type=vulnerabilities

Microsoft:
http://www.microsoft.com/technet/security/Bulletin/MS05-020.mspx

--
