Secunia Research Advisory

ClamAV Upack Processing Buffer Overflow Vulnerability


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                     Secunia Research 14/04/2008

      - ClamAV Upack Processing Buffer Overflow Vulnerability -

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Table of Contents

Affected Software....................................................1
Severity.............................................................2
Vendor's Description of Software.....................................3
Description of Vulnerability.........................................4
Solution.............................................................5
Time Table...........................................................6
Credits..............................................................7
References...........................................................8
About Secunia........................................................9
Verification........................................................10

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1) Affected Software 

* ClamAV 0.92 and 0.92.1.

NOTE: Prior versions may also be affected.

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2) Severity 

Rating: Highly critical
Impact: System access
Where: From remote

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3) Vendor's Description of Software 

"Clam AntiVirus is an open source (GPL) anti-virus toolkit for UNIX, 
designed especially for e-mail scanning on mail gateways."

Product Link:
http://clamav.net/

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4) Description of Vulnerability

Secunia Research has discovered a vulnerability in ClamAV, which can 
be exploited by malicious people to compromise a vulnerable system.

The vulnerability is caused due to a boundary error within the 
"cli_scanpe()" function in libclamav/pe.c. This can be exploited to 
cause a heap-based buffer overflow via a specially crafted "Upack" 
executable.

Successful exploitation allows execution of arbitrary code.

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5) Solution 

An updated version should be available shortly. The PE scanning module
has been remotely switched off after 10/03/2008.

Do not scan untrusted PE files.

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6) Time Table 

10/03/2008 - Vendor notified.
10/03/2008 - vendor-sec notified.
10/03/2008 - Vendor response.
14/04/2008 - Public disclosure.

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7) Credits 

Discovered by Alin Rad Pop, Secunia Research.

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8) References

The Common Vulnerabilities and Exposures (CVE) project has assigned 
CVE-2008-1100 for the vulnerability.

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9) About Secunia

Secunia offers vulnerability management solutions to corporate
customers with verified and reliable vulnerability intelligence
relevant to their specific system configuration:

https://www.flexera.com/

Secunia also provides a publicly accessible and comprehensive advisory
database as a service to the security community and private 
individuals, who are interested in or concerned about IT-security.

Secunia believes that it is important to support the community and to
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security and reliability of software in general.

Secunia regularly hires new skilled team members. Check the URL below
to see currently vacant positions:

https://www.flexera.com/company/careers

Secunia offers a FREE mailing list called Secunia Security Advisories:

https://www.flexera.com/secunia_security_advisories/ 

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10) Verification 

Please verify this advisory by visiting the Secunia website:
https://www.flexera.com/about-us/secunia-research/advisories/sr-2008-11.html

Complete list of vulnerability reports published by Secunia Research:
https://www.flexera.com/about-us/secunia-research/advisories/

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