A double-free flaw was found in the way OpenLDAP's slapd server using the MDB backend handled LDAP searches. A remote attacker with access to search the directory could potentially use this flaw to crash slapd by issuing a specially crafted LDAP search query (CVE-2017-9287).
The openldap package has been updated to version 2.4.45 to fix this issue and other bugs.