Best Practical Solutions RT 3.x before 3.8.12 and 4.x before 4.0.6 allows remote authenticated users to read (1) hashes of former passwords and (2) ticket correspondence history by leveraging access to a privileged account.
http://www.securityfocus.com/bid/53660
http://secunia.com/advisories/49259
http://lists.bestpractical.com/pipermail/rt-announce/2012-May/000204.html
http://lists.bestpractical.com/pipermail/rt-announce/2012-May/000203.html
http://lists.bestpractical.com/pipermail/rt-announce/2012-May/000202.html