CVE-2011-1005
The safe-level feature in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through 1.8.7-330, and 1.8.8dev allows context-dependent attackers to modify strings via the Exception#to_s method, as demonstrated by changing an intended pathname.
Date published : 2011-03-02
http://lists.apple.com/archives/security-announce/2012/May/msg00001.html