TSRT-06-02: Microsoft SRV.SYS Mailslot Ring0 Memory Corruption
July 11, 2006
-- CVE ID:
-- Affected Vendor:
-- Affected Products:
Windows XP SP1
Windows XP SP2
Windows 2003 SP1
-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability since July 11, 2006 by Digital Vaccine protection
filter ID 4266. For further product information on the TippingPoint IPS:
-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of the Microsoft Windows operating system.
Authentication is not required to exploit this vulnerability and code
execution occurs within the context of the kernel.
According to the Microsoft Developer Network (MSDN) documentation,
Mailslot communications are divided into two classes. First-class
Mailslots are connection oriented and operate over SMB/TCP.
Second-class Mailslots provide connectionless messaging for broadcast
messages and operate over SMB/UDP. Second-class Mailslots are limited
to 424 bytes per message. First-class Mailslots are officially
unsupported in the Windows 2000, XP and 2003 operating systems.
The specific flaw exists within the SRV.SYS driver, which is
responsible for handling all Server Message Block (SMB) traffic. During
the processing of first-class Mailslot messages, an exploitable memory
corruption condition is created. As a side effect, attackers are also
capable of exceeding the second-class Mailslot message size
It is important to note that this vulnerability affects more than just
the Windows kernel. Applications built on Mailslot communications that
rely on the message size restriction of second-class Mailslots are
likely to be affected by this vulnerability.
-- Vendor Response:
Microsoft has issued an update to correct this vulnerability. More
details can be found at:
-- Disclosure Timeline:
2006.03.01 - Vulnerability reported to vendor
2006.07.11 - Digital Vaccine released to TippingPoint customers
2006.07.11 - Coordinated public release of advisory
This vulnerability was discovered by Pedram Amini, TippingPoint Security
Research Team in collaboration with HD Moore, Metasploit.