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.
liblber/io.c in OpenLDAP 2.2.4 to 2.4.10 allows remote attackers to cause a denial of service (program termination) via crafted ASN.1 BER datagrams that trigger an assertion error.