CVE-2023-38691 (GCVE-0-2023-38691)

Vulnerability from cvelistv5 – Published: 2023-08-04 16:34 – Updated: 2024-10-07 13:01
VLAI
Title
matrix-appservice-bridge doesn't verify the sub parameter of an openId token exhange, allowing unauthorized access to provisioning APIs
Summary
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
5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-10-07 13:01 UTC
CWE
  • CWE-287 - Improper Authentication
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7963 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
matrix-org matrix-appservice-bridge Affected: >= 4.0.0, < 8.1.2
Affected: = 9.0.0
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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