The MITRE CVE dictionary describes this issue as:
The prep_reprocess_req function in do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.5 does not properly perform service-principal realm referral, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted TGS-REQ request.
Find out more about CVE-2013-1416 from the
MITRE CVE dictionary dictionary and
This issue did not affect the versions of krb5 as shipped with Red Hat Enterprise Linux 4 and 5.