Computer Associates eTrust InoTask.exe Antivirus Buffer Overflow
Vulnerability

iDefense Security Advisory 05.09.07
http://labs.idefense.com/intelligence/vulnerabilities/ 
May 09, 2007

I. BACKGROUND

Computer Associates' eTrust Antivirus is a client antivirus scanner. It
is distributed in standalone packages and also as part of the Internet
Security Suite. More information can be found on the vendor's website
at the following URL.

http://www3.ca.com/solutions/product.aspx?ID=156 

II. DESCRIPTION

Local exploitation of a buffer overflow vulnerability in Computer
Associates International Inc.'s (CA) eTrust Antivirus allows attackers
to execute arbitrary code with SYSTEM privileges.

The Task Service component of eTrust Antivirus, InoTask.exe, is used to
schedule and execute tasks such as scanning the system for virii. The
service uses a shared file mapping to share information about scheduled
tasks. The file mapping has a NULL security descriptor, which allows any
user to modify its contents. By modifying a string inside of this
mapping an attacker can trigger a stack based overflow in the InoTask
process.

III. ANALYSIS

Exploitation allows an attacker to elevate privileges to SYSTEM on the
targeted host.

A local user account is required to exploit this vulnerability; it can
not be triggered remotely.

When exploiting this vulnerability, an attacker can cause the copy
operation to write past the end of the stack. This triggers an
exception, and results in execution of attacker supplied code when
calling the SEH function.

IV. DETECTION

iDefense confirmed that CA eTrust Antivirus r8 on Windows is vulnerable.

V. WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

"CA has issued an update to address the vulnerabilities. The patched
files are available as part of the product's automatic content update."

For more information consult Computer Associates' Security Notice at the
following URL.

http://supportconnectw.ca.com/public/antivirus/infodocs/caav-secnotice050807.asp 

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-2523 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for 
security problems.

VIII. DISCLOSURE TIMELINE

02/07/2007  Initial vendor notification
02/07/2007  Initial vendor response
05/09/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was reported to iDefense by binagres.

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X. LEGAL NOTICES

Copyright =A9 2007 iDefense, Inc.

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at the time of publishing based on currently available information. Use
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