CVE-2010-4021
The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7 does not properly restrict the use of TGT credentials for armoring TGS requests, which might allow remote authenticated users to impersonate a client by rewriting an inner request, aka a "KrbFastReq forgery issue."
Date published : 2010-12-02
http://lists.apple.com/archives/security-announce/2011/Mar/msg00006.html