Ruby is an interpreted scripting language for object-oriented programming.
A bug was found in the way Ruby launched an XMLRPC server. If an XMLRPC server is launched in a certain way, it becomes possible for a remote attacker to execute arbitrary commands within the XMLRPC server. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-1992 to this issue.
Users of Ruby should update to these erratum packages, which contain a backported patch and are not vulnerable to this issue.