CVE-2023-39954: user_oidc app stores client secret unencrypted in database

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-08-10 · updated 2026-06-17
Weakness: CWE-311

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, an attacker that obtained at least read access to a snapshot of the database can impersonate the Nextcloud server towards linked servers. user_oidc 1.3.3 contains a patch. No known workarounds are available.

Affected products

nextcloud User Oidc: from 1.0.0 before 1.3.3 — fixed in 1.3.3

How to fix

Upgrade to a fixed version: nextcloud User Oidc 1.3.3. Check the vendor advisory for mitigations.

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3f92-5c8p-f6gq
https://github.com/nextcloud/user_oidc/pull/636
https://hackerone.com/reports/1994328
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3f92-5c8p-f6gq
https://github.com/nextcloud/user_oidc/pull/636
https://hackerone.com/reports/1994328

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