Off-by-one error in the UTF8StringNormalize function in OpenLDAP 2.4.26 and earlier allows remote attackers to cause a denial of service (slapd crash) via a zero-length string that triggers a heap-based buffer overflow, as demonstrated using an empty postalAddressAttribute value in an LDIF entry.

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.

Memory leak in the back-bdb backend for OpenLDAP 2.1.12 and earlier allows remote attackers to cause a denial of service (memory consumption).

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.

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.

OpenLDAP 1.2.11 and earlier improperly installs the ud binary with group write permissions, which could allow any user in that group to replace the binary with a Trojan horse.