Public Vulnerability Reports

Trend Micro AntiVirus UPX Parsing Kernel Buffer Overflow Vulnerability



The Trend Micro AntiVirus scan engine provides anti-virus capabilities to desktop, server and gateway systems. The engine is licensed to several of Trend Micro's OEM partners. More information is available on Trend Micro's web site at the following URL.


Remote exploitation of a buffer overflow vulnerability within Trend Micro's AntiVirus engine could allow an attacker to crash the scan engine or execute arbitrary code.

This vulnerability is caused by improper input validation when scanning specially crafted malformed UPX compressed executables. Memory corruption could occur leading to a invalid memory access or a potentially exploitable condition.


Exploitation allows attackers to crash the scan engine or execute arbitrary code.

This vulnerability could be used to gain unauthorized access to machines through common protocols, e.g. SMTP, HTTP, FTP. No authentication is required for an attacker to leverage this vulnerability.

Under Windows, the scan engine runs in kernel context. Under Linux, the scan engine runs as a daemon with superuser privileges. As such, an attacker can take complete control of the affected system if successful code execution is attained.


iDefense has confirmed the existence of this vulnerability in our vulnerability lab. The configurations at verification time were as follows:

  • Trend Micro's PC-Cillin Internet Security 2007
  • VsapiNI.sys (scan engine) version 3.320.0.1003

  • ServerProtect for Linux v2.5 on RHEL 4.x
  • vsapiapp version 8.310

Any implementations based on Trend Micro's AntiVirus scan engine are likely vulnerable in their default configuration.


iDefense is currently unaware of any effective workaround for this issue.


"To address this vulnerability, Trend Micro recommends customers to update to Virus Pattern File 4.245.00 or higher."

For more information, consult the Trend Micro Knowledge Base article at the link shown below.


A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not been assigned yet.


01/17/2007 Initial vendor notification
01/19/2007 Initial vendor response
02/07/2007 Coordinated public disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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Copyright © 2006 Verisign, Inc.

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