OpenDJ is an LDAPv3 compliant directory service. OpenDJ prior to 4.9.3 contains a denial-of-service (DoS) vulnerability that causes the server to become unresponsive to all LDAP requests without crashing or restarting. This issue occurs when an alias loop exists in the LDAP database. If an ldapsearch request is executed with alias dereferencing set to "always" on this alias entry, the server stops responding to all future requests. Fortunately, the server can be restarted without data corruption. This vulnerability is fixed in 4.9.3.
OpenDJ Denial of Service (DoS) using alias loop
OpenDJ Denial of Service (Dos) using alias loop