#VU77060 Improper access control in Synapse - CVE-2023-32682

Vulnerability identifier: #VU77060

Vulnerability risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-32682

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Synapse
Server applications / Conferencing, Collaboration and VoIP solutions

Vendor: Matrix.org

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper checks for deactivated users during login. A remote user can login when using uncommon configurations.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Synapse: 1.0.0 - 1.84.1

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External links
https://github.com/matrix-org/synapse/security/advisories/GHSA-26c5-ppr8-f33p
https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#password_config
https://github.com/matrix-org/synapse/pull/15624
https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html#create-or-modify-account
https://matrix-org.github.io/synapse/latest/jwt.html
https://github.com/matrix-org/synapse/pull/15634
https://github.com/matrix-org/synapse/releases/tag/v1.85.0

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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