CVE-2023-38686

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.
Configurations

Configuration 1 (hide)

cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:*

History

10 Aug 2023, 19:30

Type Values Removed Values Added
References (MISC) https://peps.python.org/pep-0476/ - (MISC) https://peps.python.org/pep-0476/ - Third Party Advisory
References (MISC) https://github.com/matrix-org/sydent/security/advisories/GHSA-p6hw-wm59-3g5g - (MISC) https://github.com/matrix-org/sydent/security/advisories/GHSA-p6hw-wm59-3g5g - Vendor Advisory
References (MISC) https://docs.python.org/3/library/ssl.html?highlight=ssl#security-considerations - (MISC) https://docs.python.org/3/library/ssl.html?highlight=ssl#security-considerations - Technical Description
References (MISC) https://github.com/matrix-org/sydent/commit/1cd748307c6b168b66154e6c4db715d4b9551261 - (MISC) https://github.com/matrix-org/sydent/commit/1cd748307c6b168b66154e6c4db715d4b9551261 - Patch
References (MISC) https://github.com/python/cpython/issues/91826 - (MISC) https://github.com/python/cpython/issues/91826 - Issue Tracking
References (MISC) https://github.com/matrix-org/sydent/pull/574 - (MISC) https://github.com/matrix-org/sydent/pull/574 - Issue Tracking, Patch
References (MISC) https://github.com/matrix-org/sydent/releases/tag/v2.5.6 - (MISC) https://github.com/matrix-org/sydent/releases/tag/v2.5.6 - Release Notes
First Time Matrix
Matrix sydent
CPE cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.3

04 Aug 2023, 17:10

Type Values Removed Values Added
New CVE

Information

Published : 2023-08-04 16:15

Updated : 2023-12-10 15:14


NVD link : CVE-2023-38686

Mitre link : CVE-2023-38686

CVE.ORG link : CVE-2023-38686


JSON object : View

Products Affected

matrix

  • sydent
CWE
CWE-295

Improper Certificate Validation