source: https://www.securityfocus.com/bid/39599/info

MIT Kerberos is prone to a remote memory-corruption vulnerability.

An authenticated attacker can exploit this issue by sending specially crafted ticket-renewal requests to a vulnerable computer.

Successfully exploiting this issue can allow the attacker to execute arbitrary code with superuser privileges, completely compromising the affected computer. Failed exploit attempts will result in a denial-of-service condition. 

The following proof-of-concept command is available:

% kinit -R

We currently are unaware of any exploits that result in code-execution.