Mandriva Linux Security Advisory 2009-193 – ext/openssl/ossl_ocsp.c in Ruby 1.8 and 1.9 does not properly check the return value from the OCSP_basic_verify function, which might allow remote attackers to successfully present an invalid X.509 certificate, possibly involving a revoked certificate. This update corrects the problem, including for older ruby versions.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/80087/MDVSA-2009-193.txt
Source: https://packetstormsecurity.com/files/80087/Mandriva-Linux-Security-Advisory-2009-193.html