Sydent is an identity server for the Matrix communications protocol. Prior to version 2.5.6, if configured to send emails using TLS, Sydent does not verify SMTP servers' certificates. This makes Sydent's emails vulnerable to interception via a man-in-the-middle (MITM) attack. Attackers with privileged access to the network can intercept room invitations and address confirmation emails. This is patched in Sydent 2.5.6. When patching, make sure that Sydent trusts the certificate of the server it is connecting to. This should happen automatically when using properly issued certificates. Those who use self-signed certificates should make sure to copy their Certification Authority certificate, or their self signed certificate if using only one, to the trust store of your operating system. As a workaround, one can ensure Sydent's emails fail to send by setting the configured SMTP server to a loopback or non-routable address under one's control which does not have a listening SMTP server.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2023-08-04T15:57:15.760Z

Updated: 2024-08-02T17:46:56.843Z

Reserved: 2023-07-24T16:19:28.363Z

Link: CVE-2023-38686

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2023-08-04T16:15:10.550

Modified: 2023-08-10T19:30:28.810

Link: CVE-2023-38686

cve-icon Redhat

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