GnuTLS: Execution of arbitrary code

Security Team Contact Address

Updated May 21, 2008

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200805-20 / gnutls
Release Date	May 21, 2008
Latest Revision	May 21, 2008: 01
Impact	high
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-libs/gnutls	< 2.2.5	>= 2.2.5	All supported architectures

Related bugreports: #222823

Synopsis

Multiple vulnerabilities might allow for the execution of arbitrary code in daemons using GnuTLS.

2. Impact Information

Background

GnuTLS is an implementation of Secure Sockets Layer (SSL) 3.0 and Transport Layer Security (TLS) 1.0, 1.1 and 1.2.

Description

Ossi Herrala and Jukka Taimisto of Codenomicon reported three vulnerabilities in libgnutls of GnuTLS:

"Client Hello" messages containing an invalid server name can lead to a buffer overflow when evaluating "Security Parameters" (CVE-2008-1948).
Multiple "Client Hello" messages can lead to a NULL pointer dereference (CVE-2008-1949).
A TLS handshake including an encrypted "Client Hello" message and an invalid record length could lead to a buffer overread (CVE-2008-1950).

Impact

Unauthenticated remote attackers could exploit these vulnerabilities to cause Denial of Service conditions in daemons using GnuTLS. The first vulnerability (CVE-2008-1948) might allow for the execution of arbitrary code with the privileges of the daemon handling incoming TLS connections.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All GnuTLS users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-libs/gnutls-2.2.5"

4. References