slapo-pcache (overlays/pcache.c) in slapd in OpenLDAP before 2.3.39, when running as a proxy-caching server, allocates memory using a malloc variant instead of calloc, which prevents an array from being initialized properly and might allow attackers to cause a denial of service (segmentation fault) via unknown vectors that prevent the array from being null terminated.

OpenLDAP before 2.3.39 allows remote attackers to cause a denial of service (slapd crash) via an LDAP request with a malformed objectClasses attribute. NOTE: this has been reported as a double free, but the reports are inconsistent.

Buffer overflow in the krbv4_ldap_auth function in servers/slapd/kerberos.c in OpenLDAP 2.4.3 and earlier, when OpenLDAP is compiled with the --enable-kbind (Kerberos KBIND) option, allows remote attackers to execute arbitrary code via an LDAP bind request using the LDAP_AUTH_KRBV41 authentication method and long credential data.