Secunia Research: KVIrc irc:// URI Handler Command Execution Vulnerability

From: Secunia Research <remove-vuln(at)secunia.com>
Date: Thu Jun 28 2007 - 09:19:18 EDT

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                     Secunia Research 26/06/2007

     - KVIrc irc:// URI Handler Command Execution 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

• KVIrc 3.2.0

NOTE: Other versions may also be affected.

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2) Severity

Rating: Moderately critical
Impact: System Access
Where: Remote

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3) Vendor's Description of Software

"KVIrc is a free portable IRC client based on the excellent Qt GUI toolkit. KVIrc is being written by Szymon Stefanek and the KVIrc Development Team with the contribution of many IRC addicted developers around the world.".

Product Link: http://www.kvirc.net

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4) Description of Vulnerability

Secunia Research has discovered a vulnerability in KVIrc, which can be exploited by malicious people to compromise a user's system.

The vulnerability is caused due to the "parseIrcUrl()" function in src/kvirc/kernel/kvi_ircurl.cpp not properly sanitising parts of the URI when building the command for KVIrc's internal script system. This can be exploited to inject and execute commands for the KVIrc script system (including the "run" command, which can be leveraged to execute shell commands) by e.g. tricking a user into opening a specially crafted "irc://" or similar URI (e.g. "irc6://").

Successful exploitation requires that KVIrc is the default handler for "irc://" and similar URIs.

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5) Solution

Fixed in the SVN repository.
https://svn.kvirc.de/kvirc/changeset/630/#file3

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6) Time Table

19/06/2007 - Vendor notified.
19/06/2007 - Vendor response.
21/06/2007 - Vendor commits fix into SVN repository.
26/06/2007 - Public disclosure.

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7) Credits

Discovered by Stefan Cornelius, Secunia Research.

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8) References

The Common Vulnerabilities and Exposures (CVE) project has assigned CVE-2007-2951 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:

http://corporate.secunia.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.

http://secunia.com/

Secunia believes that it is important to support the community and to do active vulnerability research in order to aid improving the security and reliability of software in general:

http://corporate.secunia.com/secunia_research/33/

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

http://secunia.com/secunia_vacancies/

Secunia offers a FREE mailing list called Secunia Security Advisories:

http://secunia.com/secunia_security_advisories/

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1. Verification

Please verify this advisory by visiting the Secunia website: http://secunia.com/secunia_research/2007-56/

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

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Received on Thu Jun 28 12:19:00 2007