So lockdown mode disables any attachment except images on their messaging app, because parsing these has often been introducing exploits.

The fascinating this is that this parsing would happen on a process which even _has_ privileges to trigger any exploits. Parsing a message should be done far far away from the core OS operations, high in userspace, by a sandboxed process that can't break anything.

Based on previously seen exploits, it seems messages are handled by rather privileged processes. I wonder if there's a reason for that (e.g.: special messages can trigger privileged operations?)