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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-2023-38691 Detail

Description

matrix-appservice-bridge provides an API for setting up bridges. Starting in version 4.0.0 and prior to versions 8.1.2 and 9.0.1, a malicious Matrix server can use a foreign user's MXID in an OpenID exchange, allowing a bad actor to impersonate users when using the provisioning API. The library does not check that the servername part of the `sub` parameter (containing the user's *claimed* MXID) is the the same as the servername we are talking to. A malicious actor could spin up a server on any given domain, respond with a `sub` parameter according to the user they want to act as and use the resulting token to perform provisioning requests. Versions 8.1.2 and 9.0.1 contain a patch. As a workaround, disable the provisioning API.


Severity



CVSS 4.0 Severity and Metrics:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.


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: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/matrix-org/matrix-appservice-bridge/commit/4c6723a5e7beda65cdf1ae5dbb882e8beaac8552 Patch 
https://github.com/matrix-org/matrix-appservice-bridge/security/advisories/GHSA-vc7j-h8xg-fv5x Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-287 Improper Authentication cwe source acceptance level NIST   Contributor acceptance level GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2023-38691
NVD Published Date:
08/04/2023
NVD Last Modified:
08/11/2023
Source:
GitHub, Inc.