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.
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Affected Vendors & Products
References
History
No history.
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
Vulnrichment
No data.
NVD
Status : Analyzed
Published: 2023-08-04T16:15:10.550
Modified: 2023-08-10T19:30:28.810
Link: CVE-2023-38686
Redhat
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