Multiple vulnerabilities has been found and corrected in krb5:
The asn1_decode_generaltime function in lib/krb5/asn.1/asn1_decode.c in
the ASN.1 GeneralizedTime decoder in MIT Kerberos 5 (aka krb5) before
1.6.4 allows remote attackers to cause a denial of service (daemon
crash) or possibly execute arbitrary code via vectors involving an
invalid DER encoding that triggers a free of an uninitialized pointer
The asn1buf_imbed function in the ASN.1 decoder in MIT Kerberos 5
(aka krb5) 1.6.3, when PK-INIT is used, allows remote attackers to
cause a denial of service (application crash) via a crafted length
value that triggers an erroneous malloc call, related to incorrect
calculations with pointer arithmetic (CVE-2009-0847).
The updated packages have been patched to correct these issues...