Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
High
Attack Vector
Network
0

CVE-2021-32659

Disclosure Date: June 16, 2021
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

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.

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CVSS V3 Severity and Metrics
Base Score:
4.9 Medium
Impact Score:
3.6
Exploitability Score:
1.2
Vector:
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
High
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
High
Availability (A):
None

General Information

Vendors

Weaknesses

Additional Info

Technical Analysis