CRAFTBOOK-2457 - Reported by Kainzo

I've received an exploit report from a member in my community - they are using [gate] signs in a protected area that they are not allowed to destroy blocks.

Here's the word for word bug report.
Break a [gate] sign in protected region.
Let the sign come back.
Collect the fences that dropped.
Repeat.
We believe this could also work for bridges and doors.

"We came to a town that was guarded by [Gates] that masons lay down. My friend was messing with me and pressing the gate randomly then he just punched it and broke it. The gate spewed out fences and then was reset, because we had no permissions to build. He broke it like 10 times and it duped tons of fence. (fences are useless so we didn't keep them)"

Comment by me4502

If you use worldguard, turn on check-worldguard-flags, if not, turn on both that and advanced-block checks.

Comment by Kainzo

check-worldguard-flags: true
advanced-block-checks: true
is already enabled for all servers, fyi
We use residence and worldguard for region management.

Comment by me4502

In that case, one of those plugins is causing the issue