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Secunia Research 13/10/2005

- AhnLab V3 Antivirus ALZ/UUE/XXE Archive Handling Buffer Overflow -

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Table of Contents

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

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1) Affected Software

AhnLab V3Pro 2004 (V3 VirusBlock 2005 international) (Build 6.0.0.457)
AhnLab V3Net for Windows Server 6.0 (Build 6.0.0.457)
AhnLab MyV3 with AzMain.dll 1.3.11.15

Prior versions may also be affected.

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2) Severity

Rating: Highly critical
Impact: System access
Where: Remote

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3) Description of Vulnerability

Secunia Research has discovered a vulnerability in AhnLab V3
Antivirus, which can be exploited by malicious people to compromise
a vulnerable system.

The vulnerability is caused due to a boundary error in the archive
decompression library when reading the filename of a compressed file
from an ALZ, UUE or XXE archive. This can be exploited to cause a
stack-based buffer overflow (ALZ), or a heap-based buffer overflow
(UUE/XXE), when a malicious ALZ/UUE/XXE archive is scanned.

Successful exploitation allows arbitrary code execution, but requires
that compressed file scanning is enabled.

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4) Solution

AhnLab V3Pro 2004 (V3 VirusBlock 2005 international):
Update to version 6.0.0.488 via Smart Update.

AhnLab V3Net for Windows Server 6.0:
Update to version 6.0.0.488 via Smart Update.

AhnLab MyV3:
The vulnerability has reportedly been fixed in the vendor's Korean
MyV3 website.

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5) Time Table

19/09/2005 - Initial vendor notification.
20/09/2005 - Initial vendor response.
13/10/2005 - Vendor releases advisory.
13/10/2005 - Public disclosure.

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6) Credits

Discovered by Tan Chew Keong, Secunia Research.

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7) References

AhnLab:
http://global.ahnlab.com/security/se...visory002.html

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8) About Secunia

Secunia collects, validates, assesses, and writes advisories regarding
all the latest software vulnerabilities disclosed to the public. These
advisories are gathered in a publicly available database at the
Secunia website:

http://secunia.com/

Secunia offers services to our customers enabling them to receive all
relevant vulnerability information to their specific system
configuration.

Secunia offers a FREE mailing list called Secunia Security Advisories:

http://secunia.com/secunia_security_advisories/

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9) Verification

Please verify this advisory by visiting the Secunia website:
http://secunia.com/secunia_research/2005-48/advisory/

Complete list of vulnerability reports published by Secunia Research:
http://secunia.com/secunia_research/

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