Vulnerability title: Denial Of Service In Sophos Anti Virus

CVE: CVE-2014-1213
Vendor: Sophos
Product: Anti Virus
Affected Version: 10.0.11/Engine 3.48.x
Fixed Version: 10.0.11/Engine 3.50
Reported by: Graham Sutherland

Details:

The following system objects do not have access control lists (ACLs) set, thus allowing any user to access and manipulate them:

Global objects (in namespace \Global, a.k.a. \BaseNamedObjects):

  $$!_EVENT_$!__
  $$!_EVENT_$!__DataUpdateRequest
  $$!_EVENT_$!__MmfMutexSAV-****
  $$!_EVENT_$!__MmfMutexSAV-Info
  $$!_EVENT_$!__ReadyForUpdateSAV-****
  $$!_EVENT_$!__ReadyForUpdateSAV-Info
  $$!_EVENT_$!__SAV-****
  $$!_EVENT_$!__SAV-Info
  $$!_EVENT_$!__StateChange
  $$!_EVENT_$!__SuspendedSAV-****
  $$!_EVENT_$!__SuspendedSAV-Info
  $$!_EVENT_$!__UpdateComplete
  $$!_EVENT_$!__UpdateMutex
  $$!_EVENT_$!__UpdateRequest
  $$!_MMMF_$!__
  SAV-****
  SAV-Info 

Session objects (in namespace \Sessions\n\BaseNamedObjects):

SophosALMonSessionInstance

Impact:

By manipulating these objects, we found that we could cause the following problems:

Local denial of service by setting a locked or fired state on all mutexes and events. Machine becomes sluggish, certain features stop working, OS locks up and eventually BSoDs. We suspect that this is caused by an object wait call (e.g. WaitForSingleObject) in a kernel thread.

False display of “ready for update” message popup by repeatedly triggering the ReadyForUpdateSAV events and UpdateComplete / UpdateMutex / UpdateRequest objects.

Exploit:

The proof of concept exploit code is available.

Vendor status:

18/10/2013 Advisory created
11/11/2013 Vendor contacted
23/11/2013 Vendor working on a fix
14/01/2014 CVE obtained
21/01/2014 Fix released (Engine v 3.50)
23/01/2014 Fix confirmed
31/01/2014 Published
Copyright:

Copyright © Portcullis Computer Security Limited 2014, All rights reserved worldwide. Permission is hereby granted for the electronic redistribution of this information. It is not to be edited or altered in any way without the express written consent of Portcullis Computer Security Limited.

Disclaimer:

The information herein contained may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user’s risk. In no event shall the author/distributor (Portcullis Computer Security Limited) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.