What is the CVSS score of CVE-2021-32659?

CVE-2021-32659 has a CVSS 3.1 base score of 4.9 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N. EPSS exploitation probability: 0.9%.

Is there a patch available for CVE-2021-32659?

Yes, a patch is available for CVE-2021-32659. Update the affected software to the latest version immediately.

Matrix CVE-2021-32659

MEDIUM

Missing Authentication for Critical Function (CWE-306)

2021-06-16 security-advisories@github.com

Authentication Bypass Matrix Matrix Appservice Bridge

4.9

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.9 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Lifecycle Timeline

CVE Published

Jun 16, 2021 - 19:15 nvd

MEDIUM 4.9

DescriptionNVD

Matrix-appservice-bridge is the bridging service for the Matrix communication program's application services. In versions 2.6.0 and earlier, if a bridge has room upgrade handling turned on in the configuration (the roomUpgradeOpts key when instantiating a new Bridge instance.), any m.room.tombstone event it encounters will be used to unbridge the current room and bridge into the target room. However, the target room m.room.create event is not checked to verify if the predecessor field contains the previous room. This means that any malicious admin of a bridged room can repoint the traffic to a different room without the new room being aware. Versions 2.6.1 and greater are patched. As a workaround, disabling the automatic room upgrade handling can be done by removing the roomUpgradeOpts key from the Bridge class options.

AnalysisAI

Matrix-appservice-bridge is the bridging service for the Matrix communication program's application services. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. This Missing Authentication for Critical Function vulnerability could allow attackers to access critical functionality without authentication.

Technical ContextAI

This vulnerability is classified as Missing Authentication for Critical Function (CWE-306), which allows attackers to access critical functionality without authentication. Matrix-appservice-bridge is the bridging service for the Matrix communication program's application services. In versions 2.6.0 and earlier, if a bridge has room upgrade handling turned on in the configuration (the roomUpgradeOpts key when instantiating a new Bridge instance.), any m.room.tombstone event it encounters will be used to unbridge the current room and bridge into the target room. However, the target room m.room.create event is not checked to verify if the predecessor field contains the previous room. This means that any malicious admin of a bridged room can repoint the traffic to a different room without the new room being aware. Versions 2.6.1 and greater are patched. As a workaround, disabling the automatic room upgrade handling can be done by removing the roomUpgradeOpts key from the Bridge class options. Affected products include: Matrix Matrix-Appservice-Bridge.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Require authentication for all sensitive operations, implement defense in depth.