CVE-2021-39164 : Exploit Details and Defense Strategies
Discover the impact, mitigation steps, and technical details of CVE-2021-39164. Learn how unauthorized users can access room membership information in specific conditions.
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 membership of a room with shared history visibility. Discover the impact, technical details, and mitigation steps below.
Understanding CVE-2021-39164
The vulnerability involves improper authorization that exposes room membership to non-members.
What is CVE-2021-39164?
This CVE allows unauthorized users in specific room conditions to access membership information.
The Impact of CVE-2021-39164
- CVSS Score: 3.1 (Low severity)
- Attack Vector: Network
- Attack Complexity: High
- Privileges Required: Low
- Unauthorized users can view room membership details in certain conditions.
Technical Details of CVE-2021-39164
Learn about the vulnerability description, affected systems, and exploitation mechanism.
Vulnerability Description
In versions prior to 1.41.1, unauthorized users can access room membership data under specific conditions.
Affected Systems and Versions
- Product: synapse
- Vendor: matrix-org
- Version: < 1.41.1
Exploitation Mechanism
The vulnerability allows unauthorized users on a vulnerable homeserver to access room membership in shared history visibility rooms.
Mitigation and Prevention
Discover immediate steps and long-term security practices to mitigate the vulnerability.
Immediate Steps to Take
- Upgrade the server to version 1.41.1 or later to receive the patch.
- Consider blocking specific endpoints with a reverse proxy if upgrading is not feasible.
Long-Term Security Practices
- Regularly update the server software to the latest versions.
- Review and adjust the server configuration to enhance security.
Patching and Updates
- Upgrade to version 1.41.1 or the latest available version to patch the vulnerability.