Public Vulnerability Reports

McAfee VirusScan On-Access Scanner Long Unicode File Name Buffer Overflow



McAfee VirusScan is an AntiVirus application that offers protection against the latest computer virus threats. More information can be found on the vendor's site at the following URL.


Remote exploitation of a buffer overflow vulnerability in McAfee's VirusScan Antivirus application allows attackers to disable the On-Access scanner or potentially execute arbitrary code with SYSTEM privileges.

The McAfee On-Access scanner component contains a common software flaw that leads to heap corruption when dealing with overly long file names that contain multi-byte characters.

This flaw only manifests itself when the target system has East Asia language files installed and the default Unicode codepage is set to a language which contains multi-byte characters such as Chinese.


Exploitation allows attackers to disable the On-Access Scanner component of McAfee VirusScan or potentially execute arbitrary code with SYSTEM privileges.

In order to exploit this vulnerability, an attacker needs to be able to place a file with an overly long file name on the victims computer. The file name would have to contain multi-byte characters such as Chinese native characters. If the On-Access scanner is enabled, simply hovering the mouse over the file to view the file properties or attempting to open the file will trigger the overflow.

Standard archive manipulation programs such as WinZip and Windows Compressed Folder viewer cannot handle files capable of exploiting this vulnerability.


iDefense has confirmed this vulnerability in McAfee VirusScan 8.0 Enterprise. Previous versions are suspected vulnerable as well.


iDefense is currently unaware of any workarounds for this issue.


McAfee has addressed this vulnerability in Patch 12 of VirusScan Enterprise 8.0i. They recommend installing the latest available patch (Patch15). More information is available in McAfee's Security Bulletin 612750 at the following URL.


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


02/08/2007 Initial vendor notification
02/08/2007 Initial vendor response
04/17/2007 Coordinated public disclosure


This vulnerability was discovered by Jun Mao (iDefense Labs).

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Copyright © 2007 Verisign, Inc.

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