A NULL pointer dereference flaw was found in 389-ds-base. This flaw occurs when a ModifyDN (rename) operation uses an attribute's schema alias name (such as "commonName") instead of its canonical name (such as "cn") as the new relative distinguished name. An authenticated attacker with the ModifyDN (rename) permission on the affected entry can use this flaw to crash the directory server, causing a denial of service.
Administrators should review custom access control instructions (ACIs) and avoid granting the ModifyDN (rename) right to non-administrative principals unless specifically required. Restricting this right reduces exposure to this issue until a fixed package is available. Neither 389-ds-base's own default ACI templates nor Red Hat Identity Management (IdM/FreeIPA)'s default ACIs grant this right to non-administrative users, so deployments that have not customized their ACIs are not exposed.