You can decrease the level of a water or powder snow cauldron, through the use of a player on fire in spawn protection

The Bug:

You can decrease the level of a water or powder snow cauldron, through the use of a player on fire in spawn protection.

Steps to Reproduce:

• Start a server and join it.

• Give operator permissions to yourself.

• Set the world spawn to your current location.

• Place some powder snow or water inside of a cauldron.

• Place some fire nearby and switch into survival mode.

• Remove your operator permissions.

• Give operator permissions to any person other than yourself.

• Stand in the fire and attempt to extinguish yourself through the use of a powder snow/water cauldron.
  → ❌  Notice how you are extinguished and the level of the water or powder snow cauldron is decreased, despite it being in spawn protection.