CVE-2023-39953 Information

Description

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.

Reference

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xx3h-v363-q36j https://github.com/nextcloud/user_oidc/pull/642 https://hackerone.com/reports/2021684