A vulnerability was discovered in the 389 Directory Server that allows an unauthenticated attacker with network access to the LDAP port to cause a denial of service. The denial of service is triggered by a single message sent over a TCP connection, no bind or other authentication is required. The message triggers a segmentation fault that results in slapd crashing.
https://lists.debian.org/debian-lts-announce/2023/04/msg00026.html
https://github.com/389ds/389-ds-base/issues/5242