When the plugin restarts it reads its persisted state file and used the
stored mountpoint verbatim. A state file written by an older rclone that
allowed escaping volume names, or one that was tampered with, could point
the mountpoint outside the base directory, so upgrading did not remediate
an already-escaped volume.
Re-derive the mountpoint from the base directory and the volume name on
restore, confined to the base directory, rather than trusting the stored
path.
Nick Craig-Wood
f5795d00c2