#VU78843 Improper Certificate Validation in Sydent - CVE-2023-38686

Vulnerability identifier: #VU78843

Vulnerability risk: Medium

CVSSv4.0: 6.2 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-38686

CWE-ID: CWE-295

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Sydent
Server applications / Directory software, identity management

Vendor: Matrix.org

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to improper validation of email server certificates. A remote attacker on the local network can perform a man-in-the-middle (MitM) attack to intercept room invitations and address confirmation emails.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Sydent: 1.0.0 - 2.5.5

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External links
https://github.com/matrix-org/sydent/releases/tag/v2.5.6
https://github.com/matrix-org/sydent/security/advisories/GHSA-p6hw-wm59-3g5g

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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