What is the CVSS score of CVE-2021-39163?

CVE-2021-39163 has a CVSS 3.1 base score of 3.1 (Low). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.9%.

Is there a patch available for CVE-2021-39163?

Yes, a patch is available for CVE-2021-39163. Update the affected software to the latest version immediately.

Synapse CVE-2021-39163

LOW

Information Exposure (CWE-200)

2021-08-31 security-advisories@github.com

Information Disclosure Synapse Fedora

3.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

3.1 LOW

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Lifecycle Timeline

CVE Published

Aug 31, 2021 - 16:15 nvd

LOW 3.1

DescriptionNVD

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.

AnalysisAI

Matrix is an ecosystem for open federated Instant Messaging and Voice over IP. Rated low severity (CVSS 3.1), this vulnerability is remotely exploitable. This Exposure of Sensitive Information vulnerability could allow attackers to access sensitive data that should not be disclosed.

Technical ContextAI

This vulnerability is classified as Exposure of Sensitive Information (CWE-200), which allows attackers to access sensitive data that should not be disclosed. 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. Affected products include: Matrix Synapse, Fedoraproject Fedora.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Minimize information in error messages, implement proper access controls, encrypt sensitive data at rest and in transit.