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NOTICE UPDATED - April, 25th 2024

NIST has updated the NVD program announcement page with additional information regarding recent concerns and the temporary delays in enrichment efforts.

CVE-2023-38686 Detail

Description

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



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  5.3 MEDIUM
Vector:  CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
Base Score:  9.3 CRITICAL
Vector:  CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://docs.python.org/3/library/ssl.html?highlight=ssl#security-considerations Technical Description 
https://github.com/matrix-org/sydent/commit/1cd748307c6b168b66154e6c4db715d4b9551261 Patch 
https://github.com/matrix-org/sydent/pull/574 Issue Tracking  Patch 
https://github.com/matrix-org/sydent/releases/tag/v2.5.6 Release Notes 
https://github.com/matrix-org/sydent/security/advisories/GHSA-p6hw-wm59-3g5g Vendor Advisory 
https://github.com/python/cpython/issues/91826 Issue Tracking 
https://peps.python.org/pep-0476/ Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-295 Improper Certificate Validation Provider acceptance level GitHub, Inc.  

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Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2023-38686
NVD Published Date:
08/04/2023
NVD Last Modified:
08/10/2023
Source:
GitHub, Inc.