CVE-2021-32659

Published Jun 16, 2021

Last updated 3 years ago

Overview

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.
Source
security-advisories@github.com
NVD status
Analyzed

Risk scores

CVSS 3.1

Type
Primary
Base score
4.9
Impact score
3.6
Exploitability score
1.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Severity
MEDIUM

CVSS 2.0

Type
Primary
Base score
3.5
Impact score
2.9
Exploitability score
6.8
Vector string
AV:N/AC:M/Au:S/C:N/I:P/A:N

Weaknesses

security-advisories@github.com
CWE-306

Social media

Hype score
Not currently trending

Configurations