Automatic room upgrade handling can be used maliciously to bridge a room non-consentually

Impact If a bridge has room upgrade handling turned on in the configuration the roomUpgradeOpts key when instantiating a new Bridge instance., any m.room.tombstone event it encounters will be used to unbridge the current room and bridge into the target room. However, the target room m.room.create...

CVE-2021-32659: Missing Authentication for Critical Function

Matrix-appservice-bridge is the bridging service for the Matrix communication program's application services. In versions 2.6.0 and earlier, if a bridge has room upgrade handling turned on in the configuration the roomUpgradeOpts key when instantiating a new Bridge instance., any m.room.tombstone...