The FileStore capability in CGI::Session for Ruby before 1.8.1, and possibly PStore, creates files with insecure permissions, which can allow local users to steal session information and hijack sessions.
secunia.com/advisories/12290/
www.debian.org/security/2004/dsa-537
www.gentoo.org/security/en/glsa/glsa-200409-08.xml
www.mandriva.com/security/advisories?name=MDKSA-2004:128
exchange.xforce.ibmcloud.com/vulnerabilities/16996
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11128