What is "Log4ShellFix"?
Log4ShellFix protects your server from the Log4Shell exploit.
Learn more about the exploit: https://www.lunasec.io/docs/blog/log4j-zero-day/

What makes this fix different from most others?
Most other fixes just check commands and chat messages. This one uses a log filter that actually checks every message (whether it is a chat message, a command, or a message from another plugin) before it is logged. It also fixes all types of the exploit, not only one.

Note: There are already some Spigot versions where the exploit is fixed.