Loading HuntDB...
Hunt
Vulnerability Intelligence by wss.sh
Home Daily Briefings High Impact CVEs Recent Exploits KEV Catalog GitHub Advisories Latest Updates Security News
Sign In Sign Up

CVE-2021-39164

LOW
Published 2021-08-31T16:20:10
Actions:

Expert Analysis

Professional remediation guidance

Get tailored security recommendations from our analyst team for CVE-2021-39164. We'll provide specific mitigation strategies based on your environment and risk profile.

CVSS Score

V3.1
3.1
/10
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Base Score Metrics
Exploitability: N/A Impact: N/A

EPSS Score

v2025.03.14
0.005
probability
of exploitation in the wild

There is a 0.5% chance that this vulnerability will be exploited in the wild within the next 30 days.

Updated: 2025-06-25
Exploit Probability
Percentile: 0.650
Higher than 65.0% of all CVEs

Attack Vector Metrics

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED

Impact Metrics

Confidentiality
LOW
Integrity
NONE
Availability
NONE

Description

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.

Available Exploits

No exploits available for this CVE.

Related News

No news articles found for this CVE.

Affected Products

matrix-org

synapse

Affected Versions:

< 1.41.1

GitHub Security Advisories

Community-driven vulnerability intelligence from GitHub

✓ GitHub Reviewed LOW

Improper authorisation of members discloses room membership to non-members

GHSA-3x4c-pq33-4w3q

Advisory Details

### Impact 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. ### Patches Server administrators should upgrade to 1.41.1 or later. ### Workarounds Administrators of servers that use a reverse proxy could, with potentially unacceptable loss of functionality, block the following endpoints: * `/_matrix/client/r0/rooms/{room_id}/members` with `at` query parameter * `/_matrix/client/unstable/rooms/{room_id}/members` with `at` query parameter ### References n/a ### For more information If you have any questions or comments about this advisory, e-mail us at [email protected].

Affected Packages

PyPI matrix-synapse
ECOSYSTEM: ≥0 <1.41.1

CVSS Scoring

CVSS Score

2.5

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

References

WEB https://github.com/matrix-org/synapse/security/advisories/GHSA-3x4c-pq33-4w3q
ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2021-39164
WEB https://github.com/matrix-org/synapse/commit/cb35df940a
PACKAGE https://github.com/matrix-org/synapse
WEB https://github.com/matrix-org/synapse/releases/tag/v1.41.1
WEB https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2021-425.yaml
WEB https://lists.fedoraproject.org/archives/list/[email protected]/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF
WEB https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN

Advisory provided by GitHub Security Advisory Database. Published: September 1, 2021, Modified: September 24, 2024

References

https://github.com/matrix-org/synapse/commit/cb35df940a
https://github.com/matrix-org/synapse/releases/tag/v1.41.1
https://github.com/matrix-org/synapse/security/advisories/GHSA-3x4c-pq33-4w3q
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/
Published: 2021-08-31T16:20:10
Last Modified: 2024-08-04T01:58:18.118Z
Copied to clipboard!