The pkinit_check_kdc_pkid function in plugins/preauth/pkinit/pkinit_crypto_openssl.c in the PKINIT implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.4 and 1.11.x before 1.11.1 does not properly handle errors during extraction of fields from an X.509 certificate, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a malformed KRB5_PADATA_PK_AS_REQ AS-REQ request.
https://github.com/krb5/krb5/commit/f249555301940c6df3a2cdda13b56b5674eebc2e
http://www.mandriva.com/security/advisories?name=MDVSA-2013:157
http://web.mit.edu/kerberos/www/krb5-1.11/
http://web.mit.edu/kerberos/www/krb5-1.10/
http://secunia.com/advisories/55040
http://lists.opensuse.org/opensuse-updates/2013-03/msg00090.html