Several functions inside OpenSSL incorrectly checked the result after
calling the EVP_VerifyFinal function, allowing a malformed signature
to be treated as a good signature rather than as an error. This issue
affected the signature checks on DSA and ECDSA keys used with
SSL/TLS.

One way to exploit this flaw would be for a remote attacker who is in
control of a malicious server or who can use a 'man in the middle'
attack to present a malformed SSL/TLS signature from a certificate chain
to a vulnerable client, bypassing validation.

This vulnerability is tracked as CVE-2008-5077.

The OpenSSL security team would like to thank the Google Security Team
for reporting this issue.
...
Users of OpenSSL 0.9.8 should update to the OpenSSL 0.9.8j release
which contains a patch to correct this issue.

The patch used is also appended to this advisory for users or
distributions who wish to backport this patch to versions they build
from source.