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Squid Proxy Cache Security Update Advisory SQUID-2013:2
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Advisory ID: SQUID-2013:2
Date: July 11, 2013
Summary: Buffer overflow in HTTP request handling
Affected versions: Squid 3.2 -> 3.2.11,
Squid 3.3 -> 3.3.6
Fixed in version: Squid 3.2.12, 3.3.7
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http://www.squid-cache.org/Advisories/SQUID-2013_2.txt
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Problem Description:
Due to incorrect data validation Squid is vulnerable to a buffer
overflow attack when processing specially crafted HTTP requests.
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Severity:
This problem allows any trusted client or client script who can
generate HTTP requests to trigger a buffer overflow in Squid,
resulting in a termination of the Squid service.
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Updated Packages:
This bug is fixed by Squid versions 3.2.12 and 3.3.7.
In addition, patches addressing the underlying problem for all
Squid versions can be found inour patch archives.
Squid 3.0:
http://www.squid-cache.org/Versions/v3/3.0/changesets/squid-3.0-9200.patch
Squid 3.1:
http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10487.patch
Squid 3.2:
http://www.squid-cache.org/Versions/v3/3.2/changesets/squid-3.2-11823.patch
Squid 3.3:
http://www.squid-cache.org/Versions/v3/3.3/changesets/squid-3.3-12587.patch
If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
packages.
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Determining if your version is vulnerable:
All Squid-3.1 and older versions, including Squid-2.x are not
vulnerable.
All unpatched Squid-3.2 versions up to and including 3.2.11 with
'intercept' or 'tproxy' option set on a http_port or https_port
line in their squid.conf are vulnerable.
All unpatched Squid-3.2 versions up to and including 3.2.11 with
'host_verify_strict' option set to ON intheir squid.conf are
vulnerable.
All unpatched Squid-3.3 versions up to and including 3.3.6 with
'intercept' or 'tproxy' option set on a http_port or https_port
line in their squid.conf are vulnerable.
All unpatched Squid-3.3 versions up to and including 3.3.6 with
'host_verify_strict' option set to ON intheir squid.conf are
vulnerable.
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Workarounds:
There are no workarounds for this issue when intercepting traffic
with NAT or TPROXY.Use of transparent auto-configuration via
WPAD and/or PAC isrecommended practice instead of interception.
If the vulnerability is due to use of the host_verify_strict
directive in squid.conf. Removing it or setting it to OFF (the
default) will remove the vulnerability for reverse-proxy and
forward-proxy traffic. Any intercepted traffic will remain
vulnerable.
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Contact details for the Squid project:
For installation / upgrade support on binary packaged versions
of Squid: Your first point of contact should be your binary
package vendor.
If your install and build Squid from the original Squid sources
then the squid-users@xxxxxxxxxxxxxxx mailing list is your primary
support point. For subscription details see
<http://www.squid-cache.org/Support/mailing-lists.html>.
For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
<http://bugs.squid-cache.org/>.
For reporting of security sensitive bugs send an email to the
squid-bugs@xxxxxxxxxxxxxxx mailing list. It's a closed list
(though anyone can post) and security related bug reports are
treated in confidence until the impact has been established.
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Credits:
The vulnerability was reported and fix provided by Nathan Hoad,
Netbox Blue Pty Ltd
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Revision history:
2013-07-10 03:25 GMT Initial Report
2013-07-10 18:45 GMT Patches Released
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