GLSA 200602-08 libtasn1, GNU TLS: Security flaw in DER decoding

Gentoo Linux Security Advisory GLSA 200602-08
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http://security.gentoo.org/
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Severity: High
Title: libtasn1, GNU TLS: Security flaw in DER decoding
Date: February 16, 2006
Bugs: #122307
ID: 200602-08

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Synopsis
========

A flaw in the parsing of Distinguished Encoding Rules (DER) has been
discovered in libtasn1, potentially resulting in the execution of
arbitrary code.

Background
==========

Libtasn1 is a library used to parse ASN.1 (Abstract Syntax Notation
One) objects, and perform DER (Distinguished Encoding Rules) decoding.
Libtasn1 is included with the GNU TLS library, which is used by
applications to provide a cryptographically secure communications
channel.

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

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 dev-libs/libtasn1 lt; 0.2.18 gt;= 0.2.18
2 net-libs/gnutls lt; 1.2.10 gt;= 1.2.10
-------------------------------------------------------------------
2 affected packages on all of their supported architectures.
-------------------------------------------------------------------

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

Evgeny Legerov has reported a flaw in the DER decoding routines
provided by libtasn1, which could cause an out of bounds access to
occur.

Impact
======

A remote attacker could cause an application using libtasn1 to crash
and potentially execute arbitrary code by sending specially crafted
input.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All libtasn1 users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=dev-libs/libtasn1-0.2.18"

All GNU TLS users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=net-libs/gnutls-1.2.10"

References
==========

[ 1 ] CVE-2006-0645
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-0645

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

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

http://security.gentoo.org/glsa/glsa-200602-08.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 2006 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/2.0