ZDI-06-045: Sophos Anti-Virus CPIO Archive Parsing Buffer Overflow Vulnerability

[zdi-disclosures@xxxxxxxx]

ZDI-06-045: Sophos Anti-Virus CPIO Archive Parsing Buffer Overflow
            Vulnerability
http://www.zerodayinitiative.com/advisories/ZDI-06-045.html
December 12, 2006

-- CVE ID:
CVE-2006-6335

-- Affected Vendor:
Sophos

-- Affected Products:
All versions of Sophos Anti-Virus < v2.40 scanning engine

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability since December 12, 2006 by Digital Vaccine protection
filter ID 4918. For further product information on the TippingPoint IPS:

    http://www.tippingpoint.com 

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Sophos Anti-Virus.

The specific flaw exists in the parsing of CPIO archives. When a long
non-null terminated filename is processed by veex.dll, a stack overflow
occurs. Exploitation is possible leading to remote code execution
running under the SYSTEM context.

-- Vendor Response:
Sophos has issued an update to correct this vulnerability. More details
can be found at:

    http://www.sophos.com/support/knowledgebase/article/17340.html

-- Disclosure Timeline:
2006.09.14 - Vulnerability reported to vendor
2006.12.12 - Digital Vaccine released to TippingPoint customers
2006.12.12 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by an anonymous researcher.

-- About the Zero Day Initiative (ZDI):
Established by TippingPoint, a division of 3Com, The Zero Day Initiative
(ZDI) represents a best-of-breed model for rewarding security
researchers for responsibly disclosing discovered vulnerabilities.

Researchers interested in getting paid for their security research
through the ZDI can find more information and sign-up at:

    http://www.zerodayinitiative.com

The ZDI is unique in how the acquired vulnerability information is used.
3Com does not re-sell the vulnerability details or any exploit code.
Instead, upon notifying the affected product vendor, 3Com provides its
customers with zero day protection through its intrusion prevention
technology. Explicit details regarding the specifics of the
vulnerability are not exposed to any parties until an official vendor
patch is publicly available. Furthermore, with the altruistic aim of
helping to secure a broader user base, 3Com provides this vulnerability
information confidentially to security vendors (including competitors)
who have a vulnerability protection or mitigation product.