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Squid LDAP authentication routines fail to check for invalid input

Vulnerability Note VU#924198

Original Release Date: 2005-02-04 | Last Revised: 2005-02-11

Overview

The Squid LDAP authentication routine squid_ldap_auth() fails to check for input characters, such as whitespace, that could be misused to possibly bypass access restrictions.

Description

Squid functions as a web proxy and cache application for a number of protocols, and includes support for lightweight directory access protocol (LDAP) authentication. However, the squid_ldap_auth() function does not properly check for and sanitize input containing whitespace. This may allow remote attackers to log in using variants of existing user names, leading to bypass of security restrictions or creation of arbitrary accounting data.

Impact

Remote attackers may be able to gain elevated privileges or could pollute accounting data with invalid entries. This flaw is platform independent.

Solution

Apply an update

Administrators should obtain an updated version of Squid from their vendor if LDAP authentication is used.

Team Squid has created a patch for the current release version of Squid: squid-2.5.STABLE7-ldap_spaces.patch

This flaw has been patched in Squid 2.5.STABLE8-RC4. More details are available in the Squid Bugzilla bug #1187.

Squid administrators may either disable LDAP authentication or block usernames containing whitespace as a workaround.

Vendor Information

924198
 

Squid Affected

Updated:  February 04, 2005

Status

Affected

Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

Team Squid has created a patch for the current release version of Squid: squid-2.5.STABLE7-ldap_spaces.patch

This flaw has been patched in Squid 2.5.STABLE8-RC4. More details are available in the Squid Bugzilla bug #1187.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


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References

Acknowledgements

Thanks to Team Squid for reporting this vulnerability, who in turn credit Andrew P with the discovery of this flaw.

This document was written by Ken MacInnis based primarily on information provided by Team Squid.

Other Information

CVE IDs: CVE-2005-0173
Severity Metric: 6.30
Date Public: 2005-01-17
Date First Published: 2005-02-04
Date Last Updated: 2005-02-11 22:01 UTC
Document Revision: 25

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