Upgrade to rails 2.3.15 to fix following security issues:

https://groups.google.com/forum/?fromgroups=#!topic/rubyonrails-security/DCNTNp_qjFM
(note - the patch mentioned in the advisory was included in release 2.3.15)

https://groups.google.com/forum/#!topic/rubyonrails-security/61bkgvnSGTQ/discussion