Using the Codenomicon LDAPv3 test suite, Ilkka Mattila and Tuomas Salomäki discovered that the slap_modrdn2mods function in modrdn.c in OpenLDAP does not check the return value from a call to the smr_normalize function. A remote attacker could use specially crafted modrdn requests to crash the slapd daemon or possibly execute arbitrary code. Using the Codenomicon LDAPv3 test suite, Ilkka Mattila and Tuomas Salomäki discovered that OpenLDAP does not properly handle empty RDN strings. A remote attacker could use specially crafted modrdn requests to crash the slapd daemon. In the default installation under Ubuntu 8.04 LTS and later, attackers would be isolated by the OpenLDAP AppArmor profile for the slapd daemon.