Synopsis

Moderate: openssl security update

Type/Severity

Security Advisory: Moderate

Topic

Updated openssl packages that fix one security issue are now available for
Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL v2/v3)
and Transport Layer Security (TLS v1) protocols, as well as a
full-strength, general purpose cryptography library.

A ciphersuite downgrade flaw was found in the OpenSSL SSL/TLS server code.
A remote attacker could possibly use this flaw to change the ciphersuite
associated with a cached session stored on the server, if the server
enabled the SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG option, possibly
forcing the client to use a weaker ciphersuite after resuming the session.
(CVE-2010-4180)

Note: With this update, setting the SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
option has no effect and this bug workaround can no longer be enabled.

All OpenSSL users should upgrade to these updated packages, which contain a
backported patch to resolve this issue. For the update to take effect, all
services linked to the OpenSSL library must be restarted, or the system
rebooted.

Solution

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

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 659462 - CVE-2010-4180 openssl: NETSCAPE_REUSE_CIPHER_CHANGE_BUG ciphersuite downgrade attack

CVEs

• CVE-2010-4180

References