Secunia Research: SquirrelMail Change_passwd Plugin Insecure Temporary File Creation

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                     Secunia Research 23/04/2004 

- SquirrelMail Change_passwd Plugin Insecure Temporary File Creation -

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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
About Secunia........................................................8
Verification.........................................................9

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1) Affected Software 

Change_passwd versions prior to 4.0.

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2) Severity 

Rating:  Less Critical 
Impact:  Privilege Escalation
Where:   Local System

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3) Vendor's Description of Software 

"If your email users are system users, this plugin allow your users to
change his/her system password in /etc/passwd or /etc/shadow.".

Product link:
http://www.squirrelmail.org/plugin_view.php?id=117

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4) Description of Vulnerability 

Secunia Research has discovered a vulnerability in the Change_passwd
plugin for SquirrelMail, which can be exploited by malicious, local
users to gain escalated privileges.

The chpasswd utility creates a temporary file insecurely when updating a
user's password. This can be exploited via symlink attacks to read the
content of "/etc/shadow" or overwrite arbitrary files with "root"
privileges.

The vulnerability has been confirmed in version 3.1 of the plugin. Prior
versions are likely also affected.

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5) Solution 

Update to version 4.0 or later.

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6) Time Table 

20/04/2004 - Vulnerability discovered. 
20/04/2004 - Vendor notified.
20/04/2004 - Vendor confirms vulnerability.
23/04/2004 - Vendor issues fixed version.
23/04/2004 - Public disclosure.

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7) Credits 

Discovered by Carsten Eiram, Secunia Research.

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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/2004-4/
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