Updated OpenSSL packages that fix various security issues are now available.
This update has been rated as having moderate security impact by the Red
Hat Security Response Team.
OpenSSL is a toolkit that implements Secure Sockets Layer (SSL v2/v3) and
Transport Layer Security (TLS v1) protocols as well as a full-strength
general purpose cryptography library.
OpenSSL contained a software work-around for a bug in SSL handling in
Microsoft Internet Explorer version 3.0.2. This work-around is enabled in
most servers that use OpenSSL to provide support for SSL and TLS. Yutaka
Oiwa discovered that this work-around could allow an attacker, acting as a
"man in the middle" to force an SSL connection to use SSL 2.0 rather than a
stronger protocol such as SSL 3.0 or TLS 1.0. The Common Vulnerabilities
and Exposures project (cve.mitre.org) has assigned the name CAN-2005-2969
to this issue.
A bug was also fixed in the way OpenSSL creates DSA signatures. A cache
timing attack was fixed in RHSA-2005-476 which caused OpenSSL to do private
key calculations with a fixed time window. The DSA fix for this was not
complete and the calculations are not always performed within a
fixed-window. The Common Vulnerabilities and Exposures project
(cve.mitre.org) has assigned the name CAN-2005-0109 to this issue.
Users are advised to upgrade to these updated packages, which remove the
MISE 3.0.2 work-around and contain patches to correct these issues.
Note: After installing this update, users are advised to either
restart all services that use OpenSSL or restart their system.