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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities
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CVE-2021-39163 Detail

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`.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/matrix-org/synapse/commit/cb35df940a Patch  Third Party Advisory 
https://github.com/matrix-org/synapse/releases/tag/v1.41.1 Release Notes  Third Party Advisory 
https://github.com/matrix-org/synapse/security/advisories/GHSA-jj53-8fmw-f2w2 Mitigation  Third Party Advisory 
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/

Weakness Enumeration

CWE-ID CWE Name Source
CWE-863 Incorrect Authorization cwe source acceptance level NIST  
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

6 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-39163
NVD Published Date:
08/31/2021
NVD Last Modified:
11/06/2023
Source:
GitHub, Inc.