The rwm overlay in OpenLDAP 2.4.23, 2.4.36, and earlier does not properly count references, which allows remote attackers to cause a denial of service (slapd crash) by unbinding immediately after a search request, which triggers rwm_conn_destroy to free the session context while it is being used by rwm_op_search.

The default slapd configuration in the Debian openldap package 2.4.23-3 through 2.4.39-1.1 allows remote authenticated users to modify the user's permissions and other user attributes via unspecified vectors.

The deref_parseCtrl function in servers/slapd/overlays/deref.c in OpenLDAP 2.4.13 through 2.4.40 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via an empty attribute list in a deref control in a search request.

slapd in OpenLDAP before 2.4.30 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via an LDAP search query with attrsOnly set to true, which causes empty attributes to be returned.

libraries/libldap/tls_m.c in OpenLDAP, possibly 2.4.31 and earlier, when using the Mozilla NSS backend, always uses the default cipher suite even when TLSCipherSuite is set, which might cause OpenLDAP to use weaker ciphers than intended and make it easier for remote attackers to obtain sensitive information.