The WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN) plugin for WordPress is vulnerable to Authentication Bypass via OIDC Nonce Replay in all versions up to, and including, 44.1 This is due to `Id_Token_Service_Deprec…

Overview

The WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN) plugin for WordPress is vulnerable to Authentication Bypass via OIDC Nonce Replay in all versions up to, and including, 44.1 This is due to Id_Token_Service_Deprecated::process_openidconnect_token() using the incompatible WordPress core wp_verify_nonce() function to validate a nonce produced by Nonce_Service::create_nonce() — a 64-character hex value that wp_verify_nonce() can never successfully verify — causing the nonce check to silently fail without terminating authentication, so execution continues into authenticate_oidc_user() with the attacker-supplied id_token. This makes it possible for unauthenticated attackers who have obtained a previously-issued, valid id_token for a target account to replay that token and authenticate as any WordPress user, including administrators, resulting in full site takeover. This vulnerability is only exploitable when the use_id_token_parser_v2 plugin option is enabled, as this is the configuration that routes token processing through the deprecated parser containing the broken nonce check.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.