(RHSA-2003:063) openssl security update

OpenSSL is a commercial-grade, full-featured, open source toolkit which
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.

In a paper, Brice Canvel, Alain Hiltgen, Serge Vaudenay, and Martin
Vuagnoux describe and demonstrate a timing-based attack on CBC ciphersuites
in SSL and TLS. An active attacker may be able to use timing observations
to distinguish between two different error cases: cipher padding errors and
MAC verification errors. Over multiple connections this can leak
sufficient information to be able to retrieve the plaintext of a common,
fixed block.

In order for an attack to be sucessful an attacker must be able to act as a
man-in-the-middle to intercept and modify multiple connections which all
involve a common fixed plaintext block (such as a password), and have good
network conditions that allow small changes in timing to be reliably observed.

These updated packages contain a patch provided by the OpenSSL group that
corrects this vulnerability.

Because server applications are affected by these vulnerabilities, we
advise users to restart all services that use OpenSSL functionality or
alternatively reboot their systems after installing these updates.