Denial of service in Matrix Synapse

1) Resource exhaustion

EUVDB-ID: #VU76261

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-2022-41952

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

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

The vulnerability exists due to application does not properly control consumption of internal resources when generating URL previews for media stream. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Synapse: before 1.53.0

External links

http://github.com/matrix-org/synapse/security/advisories/GHSA-4822-jvwx-w47h
http://github.com/matrix-org/synapse/pull/11936
http://github.com/matrix-org/synapse/releases/tag/v1.53.0
http://github.com/matrix-org/synapse/releases/tag/v1.52.0
http://github.com/matrix-org/synapse/pull/11784

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.