Comodo Antivirus Evasion/bypass

Release mode: Coordinated but limited disclosure.
Ref : TZO-142009 - Comodo evasion RAR
Vendor : http://www.comodo.com
Status : Patched
Security notification reaction rating : Good
Notification to patch window : 41 days

Disclosure Policy : http://blog.zoller.lu/2008/09/notification-and-disclosure-policy.html

Affected products :

• Comodo Internet Security 3.5.x and 3.8.x (Impact low due to on access scan)
• Comodo Anti-Virus (Impact low due to on access scan)
  

I. Background
Quote: "Comodo's range of solutions gives businesses the ability to create online trust through proprietary technology that help e-businesses convert more customers, retain more customers and increase lifetime value."

II. Description
The parsing engine can be bypassed by a specially crafted and formated RAR archive. Details are currently witheld due to other vendors that are in process of deploying patches.

III. Impact
A general description of the impact and nature of AV Bypasses/evasions can be read at :
http://blog.zoller.lu/2009/04/case-for-av-bypassesevasions.html

The bug results in denying the engine the possibility to inspect code within the RAR archive. There is no inspection of the content at all and hence the impossibility to detect malicious code.


IV. Disclosure timeline
DD/MM/YYYY

• 14/03/2009 : Send proof of concept, description the terms under which I cooperate and the planned disclosure date
  

No reply

• 16/03/2009 : Resend notification
  
  
• 23/03/2009 : Comodo answers that the bug has been fixed and will be deployed in version 3.9 due in end of april.
  
  
• 02/04/2009 : Ask for affected versions.
  
  
• 02/04/2009 : Comodo answers that the ranges 3.5.x and 3.8.x have been affected and that the sheduled release date is the 25th of April. Credit will be given in the release notes.
  
  
• 27/04/2009 : Notify comodo that I plan to release the advisory today and assume the production code has been released in the 25.04.2009
  
  
• 27/04/2009 : Release of this advisory