slapd in OpenLDAP 2.0 through 2.0.19 allows local users, and anonymous users before 2.0.8, to conduct a "replace" action on access controls without any values, which causes OpenLDAP to delete non-mandatory attributes that would otherwise be protected by ACLs.
OpenLDAP 1.0 through 2.1.19, as used in Apple Mac OS 10.3.4 and 10.3.5 and possibly other operating systems, may allow certain authentication schemes to use hashed (crypt) passwords in the userPassword attribute as if they were plaintext passwords, which allows remote attackers to re-use hashed passwords without decrypting them.
OpenLDAP before 2.3.29 allows remote attackers to cause a denial of service (daemon crash) via LDAP BIND requests with long authcid names, which triggers an assertion failure.
An issue was discovered in OpenLDAP 2.x before 2.4.48. When using SASL authentication and session encryption, and relying on the SASL security layers in slapd access controls, it is possible to obtain access that would otherwise be denied via a simple bind for any identity covered in those ACLs. After the first SASL bind is completed, the saslssf value is retained for all new non-SASL connections. Depending on the ACL configuration, this can affect different types of operations (searches, modifications, etc.). In other words, a successful authorization step completed by one user affects the authorization requirement for a different user.
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 krbv4ldapauth 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 LDAPAUTHKRBV41 authentication method and long credential data.
slapd in OpenLDAP 1.x before 1.2.12, and 2.x before 2.0.8, allows remote attackers to cause a denial of service (crash) via an invalid Basic Encoding Rules (BER) length field.
ldbmbackexoppasswd in the back-ldbm backend in passwd.c for OpenLDAP 2.1.12 and earlier, when the slappasswdparse function does not return LDAPSUCCESS, attempts to free an uninitialized pointer, which allows remote attackers to cause a denial of service (segmentation fault).