CVE-2023-39953: Issuer not verified from obtained token in user_oidc
First published: Thu Aug 10 2023(Updated: )
user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in version 1.0.0 and prior to version 1.3.3, missing verification of the issuer would have allowed an attacker to perform a man-in-the-middle attack returning corrupted or known token they also have access to. user_oidc 1.3.3 contains a patch. No known workarounds are available.
Credit: security-advisories@github.com security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Nextcloud User Oidc | >=1.0.0<1.3.3 |
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Reference Links
Frequently Asked Questions
What is CVE-2023-39953?
CVE-2023-39953 is a vulnerability in the user_oidc plugin for Nextcloud, which allowed an attacker to perform a man-in-the-middle attack by bypassing issuer verification.
What is the severity of CVE-2023-39953?
CVE-2023-39953 has a severity keyword of medium and a severity value of 4.8.
How does CVE-2023-39953 affect Nextcloud?
CVE-2023-39953 affects Nextcloud instances that have the user_oidc plugin installed and are running versions prior to 1.3.3.
How can I fix CVE-2023-39953?
To fix CVE-2023-39953, you should update the user_oidc plugin to version 1.3.3 or later.
Where can I find more information about CVE-2023-39953?
More information about CVE-2023-39953 can be found in the following references: [link1], [link2], [link3].
- collector/nvd-api
- collector/nvd-index
- agent/author
- agent/type
- agent/remedy
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/weakness
- agent/last-modified-date
- agent/title
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- vendor/nextcloud
- canonical/nextcloud user oidc
- version/nextcloud user oidc/1.0.0