CVE-2021-39164

EUVD-2021-0132
Matrix is an ecosystem for open federated Instant Messaging and Voice over IP. In versions 1.41.0 and prior, unauthorised users can access the membership (list of members, with their display names) of a room if they know the ID of the room. The vulnerability is limited to rooms with `shared` history visibility. Furthermore, the unauthorised user must be using an account on a vulnerable homeserver that is in the room. Server administrators should upgrade to 1.41.1 or later in order to receive the patch. One workaround is available. Administrators of servers that use a reverse proxy could, with potentially unacceptable loss of functionality, block the endpoints: `/_matrix/client/r0/rooms/{room_id}/members` with `at` query parameter, and `/_matrix/client/unstable/rooms/{room_id}/members` with `at` query parameter.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
3.1 LOW
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
GitHub_MCNA
3.1 LOW
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 64%
Affected Products (NVD)
VendorProductVersion
matrixsynapse
𝑥
< 1.41.1
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
matrix-synapse
sid
1.116.0-3
fixed
trixie
1.116.0-3
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
matrix-synapse
bionic
needed
focal
needed
hirsute
ignored
impish
ignored
jammy
needs-triage
kinetic
ignored
lunar
not-affected
mantic
not-affected
noble
not-affected
trusty
dne
xenial
ignored