A vulnerability results from the Net::HTTPS library from Ruby versions 1.8.5 and 1.8.6 failing to validate the name on the SSL certificate against the DNS name requested by the user. By not validating the name, the library allows an attacker to present a cryptographically valid certificate with an invalid CN.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/59675/2007-006-RubySSL.txt
Source: https://packetstormsecurity.com/files/59675/Trustix-Secure-Linux-Security-Advisory-2007.6.html