CVE-2023-38686 (GCVE-0-2023-38686)
Vulnerability from cvelistv5 – Published: 2023-08-04 15:57 – Updated: 2024-10-08 17:50
VLAI
EPSS
VEX
Title
Sydent does not verify email server certificates
Summary
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.
Severity
9.3 (Critical)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-10-08 17:45 UTC
CWE
- CWE-295 - Improper Certificate Validation
Assigner
GitHub_M
CNA
References
7 references
| URL | Tags |
|---|---|
| https://github.com/matrix-org/sydent/security/adv… | x_refsource_CONFIRM |
| https://github.com/python/cpython/issues/91826 | x_refsource_MISC |
| https://github.com/matrix-org/sydent/pull/574 | x_refsource_MISC |
| https://github.com/matrix-org/sydent/commit/1cd74… | x_refsource_MISC |
| https://docs.python.org/3/library/ssl.html?highli… | x_refsource_MISC |
| https://github.com/matrix-org/sydent/releases/tag… | x_refsource_MISC |
| https://peps.python.org/pep-0476/ | x_refsource_MISC |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| matrix-org | sydent |
Affected:
< 2.5.6
|
|
| matrix | sydent |
Affected:
0 , < 2.5.6
(custom)
cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:* |
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