5 - RHSA-2010:0221

Problem Description:

An updated squid package that fixes two security issues and several bugs is now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

RHEL Desktop Workstation (v. 5 client) - i386, x86_64 Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64

3. Description:

Squid is a high-performance proxy caching server for web clients, supporting FTP, Gopher, and HTTP data objects.

A flaw was found in the way Squid processed certain external ACL helper HTTP header fields that contained a delimiter that was not a comma. A remote attacker could issue a crafted request to the Squid server, causing excessive CPU use (up to 100%). (CVE-2009-2855)

Note: The CVE-2009-2855 issue only affected non-default configurations that use an external ACL helper script.

A flaw was found in the way Squid handled truncated DNS replies. A remote attacker able to send specially-crafted UDP packets to Squid's DNS client port could trigger an assertion failure in Squid's child process, causing that child process to exit. (CVE-2010-0308)

This update also fixes the following bugs:

* Squid's init script returns a non-zero value when trying to stop a stopped service. This is not LSB compliant and can generate difficulties in cluster environments. This update makes stopping LSB compliant. (BZ#521926)

* Squid is not currently built to support MAC address filtering in ACLs. This update includes support for MAC address filtering. (BZ#496170)

* Squid is not currently built to support Kerberos negotiate authentication. This update enables Kerberos authentication. (BZ#516245)

* Squid does not include the port number as part of URIs it constructs when configured as an accelerator. This results in a 403 error. This update corrects this behavior. (BZ#538738)

* the error_map feature does not work if the same handling is set also on the HTTP server that operates in deflate mode. This update fixes this issue. (BZ#470843)

All users of squid should upgrade to this updated package, which resolves these issues. After installing this update, the squid service will be restarted automatically.

4. Solution:

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at http://kbase.redhat.com/faq/docs/DOC-11259

5. Bugs fixed (http://bugzilla.redhat.com/):

496170 - Add arp filter option 516245 - negotiate support not enabled in squid (for kerberized sso) 518182 - CVE-2009-2855 DoS (100% CPU use) while processing certain external ACL helper HTTP headers 521926 - squid 'stop after stop' is not LSB compliant 538738 - Squid accelerator mode works only if port 80 is opened 556389 - CVE-2010-0308 squid: temporary DoS (assertion failure) triggered by truncated DNS packet (SQUID-2010:1)