[ GLSA 200609-15 ] GnuTLS: RSA Signature Forgery
From: Sune Kloppenborg Jeppesen <jaervosz@gentoo.org.>
To: gentoo-announce@gentoo.org
Subject: [ GLSA 200609-15 ] GnuTLS: RSA Signature Forgery
Date: Tue, 26 Sep 2006 17:28:02 +0200
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Organization: Gentoo Linux Security Team
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Gentoo Linux Security Advisory GLSA 200609-15
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http://security.gentoo.org/
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Severity: Normal
Title: GnuTLS: RSA Signature Forgery
Date: September 26, 2006
Bugs: #147682
ID: 200609-15
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Synopsis
========
GnuTLS fails to handle excess data which could allow an attacker to
forge a PKCS #1 v1.5 signature.
Background
==========
GnuTLS is an implementation of SSL 3.0 and TLS 1.0.
Affected packages
=================
-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 net-libs/gnutls < 1.4.4 >= 1.4.4
Description
===========
verify.c fails to properly handle excess data in
digestAlgorithm.parameters field while generating a hash when using an
RSA key with exponent 3. RSA keys that use exponent 3 are commonplace.
Impact
======
Remote attackers could forge PKCS #1 v1.5 signatures that are signed
with an RSA key, preventing GnuTLS from correctly verifying X.509 and
other certificates that use PKCS.
Workaround
==========
There is no known workaround at this time.
Resolution
==========
All GnuTLS users should update both packages:
# emerge --sync
# emerge --update --ask --verbose ">=net-libs/gnutls-1.4.4"
References
==========
[ 1 ] CVE-2006-4790
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-4790
Availability
============
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:
http://security.gentoo.org/glsa/glsa-200609-15.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/2.5
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