TYPO3-EXT-SA-2025-001: Account Takeover in extension "OpenID Connect Authentication" (oidc)

Problem Description

A vulnerability in the account linking logic of the extension allows a pre-hijacking attack leading to Account Takeover. The attack can only be exploited if the following requirements are met:

• An attacker can anticipate the email address of the user.
• An attacker can register a public frontend user account using that email address before the user's first OIDC login.
• The IDP returns the field email containing the email address of the user

Solution

An updated versions 4.0.0 is available from the TYPO3 extension manager, packagist and at https://extensions.typo3.org/extension/download/oidc/4.0.0/zip

Users of the extension are advised to update the extension as soon as possible.