CVE-2023-39958: Missing brute force protection on password reset token OAuth2 API controller
Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 22.0.0 and prior to versions 22.2.10.13, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1, missing protection allows an attacker to brute force the client secrets of configured OAuth2 clients. Nextcloud Server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 22.2.10.13, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2023-39958?
CVE-2023-39958 is a vulnerability in Nextcloud Server that allows an attacker to brute force the client secrets of configured OAuth2 clients.
What is the severity of CVE-2023-39958?
CVE-2023-39958 has a severity rating of 5.8 (medium).
Which versions of Nextcloud Server are affected by CVE-2023-39958?
Nextcloud Server versions 22.0.0 to 22.2.10.13, 23.0.0 to 23.0.12.8, 24.0.0 to 24.0.12.5, 25.0.0 to 25.0.9, 26.0.0 to 26.0.4, and 27.0.0 are affected by CVE-2023-39958.
How can I fix CVE-2023-39958?
To fix CVE-2023-39958, you should update Nextcloud Server to versions 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4, or 27.0.1 or later.
Where can I find more information about CVE-2023-39958?
You can find more information about CVE-2023-39958 on the [Nextcloud Security Advisories page](https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vv27-g2hq-v48h), [Nextcloud Server Pull Request](https://github.com/nextcloud/server/pull/38773), and the [HackerOne report](https://hackerone.com/reports/1258448).