slapd in OpenLDAP 2.4.45 and earlier creates a PID file after dropping privileges to a non-root account, which might allow local users to kill arbitrary processes by leveraging access to this non-root account for PID file modification before a root script executes a "kill `cat /pathname`" command, as demonstrated by openldap-initscript.

servers/slapd/back-mdb/search.c in OpenLDAP through 2.4.44 is prone to a double free vulnerability. A user with access to search the directory can crash slapd by issuing a search including the Paged Results control with a page size of 0.

The nss_parse_ciphers function in libraries/libldap/tls_m.c in OpenLDAP does not properly parse OpenSSL-style multi-keyword mode cipher strings, which might cause a weaker than intended cipher to be used and allow remote attackers to have unspecified impact via unknown vectors.

The ber_get_next function in libraries/liblber/io.c in OpenLDAP 2.4.42 and earlier allows remote attackers to cause a denial of service (reachable assertion and application crash) via crafted BER data, as demonstrated by an attack against slapd.

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.

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.

pam_ldap and nss_ldap, when used with OpenLDAP and connecting to a slave using TLS, does not use TLS for the subsequent connection if the client is referred to a master, which may cause a password to be sent in cleartext and allows remote attackers to sniff the password.