CVE-2021-39163
Matrix Room Information Disclosure
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 name, avatar, topic and number of members of a room if they know the ID of the room. This vulnerability is limited to homeservers where the vulnerable homeserver is in the room and untrusted users are permitted to create groups (communities). By default, only homeserver administrators can create groups. However, homeserver administrators can already access this information in the database or using the admin API. As a result, only homeservers where the configuration setting `enable_group_creation` has been set to `true` are impacted. Server administrators should upgrade to 1.41.1 or higher to patch the vulnerability. There are two potential workarounds. Server administrators can set `enable_group_creation` to `false` in their homeserver configuration (this is the default value) to prevent creation of groups by non-administrators. Administrators that are using a reverse proxy could, with partial loss of group functionality, block the endpoints `/_matrix/client/r0/groups/{group_id}/rooms` and `/_matrix/client/unstable/groups/{group_id}/rooms`.
INFO
Published Date :
Aug. 31, 2021, 4:15 p.m.
Last Modified :
Nov. 7, 2023, 3:37 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
1.4
Exploitability Score :
1.6
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-39163.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-39163 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-39163 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Added Reference GitHub, Inc. https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ [No types assigned] Added Reference GitHub, Inc. https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/ [No types assigned] Removed Reference GitHub, Inc. https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ Removed Reference GitHub, Inc. https://lists.fedoraproject.org/archives/list/[email protected]/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/ -
Modified Analysis by [email protected]
Dec. 21, 2021
Action Type Old Value New Value Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/ Mailing List, Third Party Advisory Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ Third Party Advisory https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ Mailing List, Third Party Advisory Changed CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* OR *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Sep. 24, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/ [No Types Assigned] -
Initial Analysis by [email protected]
Sep. 09, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:M/Au:S/C:P/I:N/A:N) Added CVSS V3.1 NIST AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Changed Reference Type https://github.com/matrix-org/synapse/commit/cb35df940a No Types Assigned https://github.com/matrix-org/synapse/commit/cb35df940a Patch, Third Party Advisory Changed Reference Type https://github.com/matrix-org/synapse/releases/tag/v1.41.1 No Types Assigned https://github.com/matrix-org/synapse/releases/tag/v1.41.1 Release Notes, Third Party Advisory Changed Reference Type https://github.com/matrix-org/synapse/security/advisories/GHSA-jj53-8fmw-f2w2 No Types Assigned https://github.com/matrix-org/synapse/security/advisories/GHSA-jj53-8fmw-f2w2 Mitigation, Third Party Advisory Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ Third Party Advisory Added CWE NIST CWE-863 Added CPE Configuration OR *cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* versions up to (excluding) 1.41.1 Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Sep. 08, 2021
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ [No Types Assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-39163 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-39163
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.14 }} 0.03%
score
0.49334
percentile