A new security update has been released for Gentoo Linux - Asterisk: Two SIP Denial of Service vulnerabilities. Here the announcement:

Gentoo Linux Security Advisory GLSA 200704-01
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http://security.gentoo.org/
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Severity: Normal
Title: Asterisk: Two SIP Denial of Service vulnerabilities
Date: April 02, 2007
Bugs: #171467
ID: 200704-01

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Synopsis
========

Asterisk is vulnerable to two Denial of Service issues in the SIP
channel.

Background
==========

Asterisk is an open source implementation of a telephone private branch
exchange (PBX).

Affected packages
=================

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 net-misc/asterisk < 1.2.14-r2 >= 1.2.14-r2
*>= 1.0.12-r2

Description
===========

The Madynes research team at INRIA has discovered that Asterisk
contains a null pointer dereferencing error in the SIP channel when
handling INVITE messages. Furthermore qwerty1979 discovered that
Asterisk 1.2.x fails to properly handle SIP responses with return code
0.

Impact
======

A remote attacker could cause an Asterisk server listening for SIP
messages to crash by sending a specially crafted SIP message or
answering with a 0 return code.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Asterisk users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose net-misc/asterisk

Note: Asterisk 1.0.x is no longer supported upstream so users should
consider upgrading to Asterisk 1.2.x.

References
==========

[ 1 ] CVE-2007-1561
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-1561
[ 2 ] CVE-2007-1594
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-1594

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

http://security.gentoo.org/glsa/glsa-200704-01.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2007 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.5