RHSA-2008:0489 - Security Advisory

Topic

Updated gnutls packages that fix several security issues are now available
for Red Hat Enterprise Linux 5.

This update has been rated as having critical security impact by the Red
Hat Security Response Team.

Description

The GnuTLS Library provides support for cryptographic algorithms and
protocols such as TLS. GnuTLS includes libtasn1, a library developed for
ASN.1 structures management that includes DER encoding and decoding.

Flaws were found in the way GnuTLS handles malicious client connections. A
malicious remote client could send a specially crafted request to a service
using GnuTLS that could cause the service to crash. (CVE-2008-1948,
CVE-2008-1949, CVE-2008-1950)

We believe it is possible to leverage the flaw CVE-2008-1948 to execute
arbitrary code but have been unable to prove this at the time of releasing
this advisory. Red Hat Enterprise Linux 5 includes applications, such as
CUPS, that would be directly vulnerable to any such an exploit, however.
Consequently, we have assigned it critical severity.

Users of GnuTLS are advised to upgrade to these updated packages, which
contain a backported patch that corrects these issues.

Solution

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.1 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.1 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.1 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.1 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 447461 - CVE-2008-1948 GNUTLS-SA-2008-1-1 GnuTLS buffer overflow
• BZ - 447462 - CVE-2008-1949 GNUTLS-SA-2008-1-2 GnuTLS null-pointer dereference
• BZ - 447463 - CVE-2008-1950 GNUTLS-SA-2008-1-3 GnuTLS memory overread flaw

CVEs

• CVE-2008-1949
• CVE-2008-1948
• CVE-2008-1950

References

• http://www.redhat.com/security/updates/classification/#critical