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Home >> Browse Vulnerability Assessment Database >> Gentoo Local Security Checks >> [GLSA-200403-11] Squid ACL [url_regex] bypass vulnerability

Vulnerability Assessment Details

[GLSA-200403-11] Squid ACL [url_regex] bypass vulnerability

Vulnerability Assessment Summary
Squid ACL [url_regex] bypass vulnerability

Detailed Explanation for this Vulnerability Assessment
The remote host is affected by the vulnerability described in GLSA-200403-11
(Squid ACL [url_regex] bypass vulnerability)

A bug in Squid permits users to bypass certain access controls by passing a
URL containing "%00" which exploits the Squid decoding function.
This may insert a NUL character into decoded URLs, which may permit users to
bypass url_regex access control lists that are enforced upon them.
In such a scenario, Squid will insert a NUL character after
the"%00" and it will make a comparison between the URL to the end
of the NUL character rather than the contents after it: the comparison does
not result in a match, and the user's request is not denied.

Impact

Restricted users may be able to bypass url_regex access control lists that
are enforced upon them which may cause unwanted network traffic as well as
a route for other possible exploits. Users of Squid 2.5STABLE4 and below
who require the url_regex features are recommended to upgrade to 2.5STABLE5
to maintain the security of their infrastructure.

Workaround

A workaround is not currently known for this issue. All users are advised
to upgrade to the latest version of Squid.

References:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-0189
http://www.squid-cache.org/Advisories/SQUID-2004_1.txt

Solution:
Squid can be updated as follows:
# emerge sync
# emerge -pv ">=www-proxy/squid-2.5.5"
# emerge ">=www-proxy/squid-2.5.5"

Network Security Threat Level: Medium

Networks Security ID:

Vulnerability Assessment Copyright: (C) 2005 Michel Arboi

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