A NULL pointer dereference in moddavlock in Apache HTTP Server 2.4.66 and earlier may allow an attacker to crash the server with a malicious request.moddavlock is not used internally by moddav or moddav_fs.
The only known use-case for moddavlock was moddavsvn from Apache Subversion earlier than version 1.2.0.
Users are recommended to upgrade to version 2.4.66, which fixes this issue, or remove moddavlock.