This indicates an attack attempt to exploit a Denial-of-Service vulnerability in 389 Directory Server.
The vulnerability is due to an error when the vulnerable software handles crafted LDAP queries. A remote attacker may be able to exploit this to cause a denial of service condition on the affected system.
Red Hat 389 Directory Server 1.4.x prior to 188.8.131.52
Red Hat 389 Directory Server 1.3.x
Denial of Service: Remote attackers can crash vulnerable systems.
Apply the most recent upgrade or patch from the vendor.