Denial of service in Matrix Synapse

1) Uncontrolled Recursion

EUVDB-ID: #VU76405

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-31052

CWE-ID: CWE-674 - Uncontrolled Recursion

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an uncontrolled recursion when handling URL previews. A remote attacker can pass a specially crafted web page to the application and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Synapse: before 1.61.1

External links

http://github.com/matrix-org/synapse/security/advisories/GHSA-22p3-qrh9-cx32
http://spec.matrix.org/v1.2/client-server-api/#get_matrixmediav3preview_url
http://github.com/matrix-org/synapse/commit/fa1308061802ac7b7d20e954ba7372c5ac292333
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGSDQ4YAITCUACAB7SXQZDJIU3IQ4CJD/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7EARKKJZ2W7WUITFDT4EG4NVATFYJQHF/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.