Ruby before 1.8.6-p114 does not reset the random seed upon forking, which makes it easier for context-dependent attackers to predict the values of random numbers by leveraging knowledge of the number sequence obtained in a different child process, a related issue to CVE-2003-0900.
https://exchange.xforce.ibmcloud.com/vulnerabilities/69157
http://www.securityfocus.com/bid/49126
http://www.redhat.com/support/errata/RHSA-2011-1581.html
http://www.openwall.com/lists/oss-security/2011/07/20/1