Updated OpenSSL096b compatibility packages that fix a remote denial of
service vulnerability are now available.
This update has been rated as having moderate security impact by the Red
Hat Security Response Team.
The OpenSSL toolkit implements Secure Sockets Layer (SSL v2/v3),
Transport Layer Security (TLS v1) protocols, and serves as a full-strength
general purpose cryptography library. OpenSSL 0.9.6b libraries are provided
for Red Hat Enterprise Linux 3 and 4 to allow compatibility with legacy
Testing performed by the OpenSSL group using the Codenomicon TLS Test Tool
uncovered a null-pointer assignment in the do_change_cipher_spec()
function. A remote attacker could perform a carefully crafted SSL/TLS
handshake against a server that uses the OpenSSL library in such a way as
to cause OpenSSL to crash. Depending on the server this could lead to a
denial of service. (CVE-2004-0079)
This issue was reported as not affecting OpenSSL versions prior to 0.9.6c,
and testing with the Codenomicon Test Tool showed that OpenSSL 0.9.6b as
shipped as a compatibility library with Red Hat Enterprise Linux 3 and 4
did not crash. However, an alternative reproducer has been written which
shows that this issue does affect versions of OpenSSL prior to 0.9.6c.
Note that Red Hat does not ship any applications with Red Hat Enterprise
Linux 3 or 4 that use these compatibility libraries.
Users of the OpenSSL096b compatibility package are advised to upgrade to
these updated packages, which contain a patch provided by the OpenSSL group
that protect against this issue.