Spoofing attack in Matrix Synapse

1) Improper Verification of Cryptographic Signature

EUVDB-ID: #VU76260

Risk: High

CVSSv4.0: 8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2018-16515

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exist due to improper signature validation. A remote attacker can spoof application events and compromise the application.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Synapse: All versions

CPE2.3

• cpe:2.3:a:matrix_org:synapse:*:*:*:*:*:*:*:*

External links

https://github.com/matrix-org/synapse/issues/3796#event-1833126269
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IRW7YR2H3ASUSYX4AO4KMY3FNVDNYW3P/
https://matrix.org/blog/2018/09/06/critical-security-update-synapse-0-33-3-1/

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.