Id:
CVE-2021-32659
Comment
:
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` event it encounters will be used to unbridge the current room and bridge into the target room. However, the target room `m.room.create` event is not checked to verify if the `predecessor` field contains the previous room. This means that any malicious admin of a bridged room can repoint the traffic to a different room without the new room being aware. Versions 2.6.1 and greater are patched. As a workaround, disabling the automatic room upgrade handling can be done by removing the `roomUpgradeOpts` key from the `Bridge` class options.
CVSSv2 Score:
3.5
Access vector:
|
NETWORK
|
Access complexity:
|
MEDIUM
|
Authentication:
|
SINGLE
|
Confidentiality impact:
|
NONE
|
Integrity impact:
|
PARTIAL
|
Availability impact:
|
NONE
|
CVSSv2 Vector:
AV:N/AC:M/Au:S/C:N/I:P/A:N
CVSSv3 Score:
4.9
Attack vector:
|
NETWORK
|
Attack complexity:
|
LOW
|
Privileges required:
|
HIGH
|
User interaction:
|
NONE
|
Scope:
|
UNCHANGED
|
Confidentiality impact:
|
NONE
|
Integrity impact:
|
HIGH
|
Availability impact:
|
NONE
|
CVSSv3 Vector:
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
References: