CVE-2021-39163
CVSS V2 Low 3.5
CVSS V3 Low 3.1
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`.
Overview
- CVE ID
- CVE-2021-39163
- Assigner
- security-advisories@github.com
- Vulnerability Status
- Analyzed
- Published Version
- 2021-08-31T16:15:07
- Last Modified Date
- 2021-12-21T14:18:29
Weakness Enumerations
CPE Configuration (Product)
| CPE | Vulnerable | Operator | Version Start | Version End |
|---|---|---|---|---|
| cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* | 1 | OR | 1.41.1 | |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 1 | OR |
CVSS Version 2
- Version
- 2.0
- Vector String
- AV:N/AC:M/Au:S/C:P/I:N/A:N
- Access Vector
- NETWORK
- Access Compatibility
- MEDIUM
- Authentication
- SINGLE
- Confidentiality Impact
- PARTIAL
- Integrity Impact
- NONE
- Availability Impact
- NONE
- Base Score
- 3.5
- Severity
- LOW
- Exploitability Score
- 6.8
- Impact Score
- 2.9
CVSS Version 3
- Version
- 3.1
- Vector String
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
- Attack Vector
- NETWORK
- Attack Compatibility
- HIGH
- Privileges Required
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality Impact
- LOW
- Availability Impact
- NONE
- Base Score
- 3.1
- Base Severity
- LOW
- Exploitability Score
- 1.6
- Impact Score
- 1.4
References
| Reference URL | Reference Tags |
|---|---|
| https://github.com/matrix-org/synapse/security/advisories/GHSA-jj53-8fmw-f2w2 | Mitigation 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/commit/cb35df940a | Patch Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PXT7ID7DNBRN2TVTETU3SYQHJKEG6PXN/ | Mailing List Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2VHDEPCZ22GJFMZCWA2XZAGPOEV72POF/ | Mailing List Third Party Advisory |
Sources
| Source Name | Source URL |
|---|---|
| NIST | https://nvd.nist.gov/vuln/detail/CVE-2021-39163 |
| MITRE | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-39163 |
History
| Created | Old Value | New Value | Data Type | Notes |
|---|---|---|---|---|
| 2022-05-10 06:40:30 | Added to TrackCVE | |||
| 2022-12-05 09:22:39 | 2021-08-31T16:15Z | 2021-08-31T16:15:07 | CVE Published Date | updated |
| 2022-12-05 09:22:39 | 2021-12-21T14:18:29 | CVE Modified Date | updated | |
| 2022-12-05 09:22:39 | Analyzed | Vulnerability Status | updated |