CVE-2026-104732
The Advanced IP Blocker plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 8.13.13 The vulnerability exists because `handle_login_action()` performs no server-side check — via transient, session marker, or equivalent — that a requester completed step-1 password authentication before processing a step-2 TOTP submission for the POSTed `user_id`; compounding this, an error branch in the function unconditionally mints a fresh `advaipbl-2fa-interim-{user_id}` nonce and delivers it in a `Location` header to any unauthenticated caller, after which `display_2fa_login_form_step_2()` renders a valid `advaipbl-2fa-verify-{user_id}` nonce in HTML — both nonces computed against a fixed `uid=0` empty-session context and therefore fully reusable by the attacker across subsequent requests. This makes it possible for unauthenticated attackers to bypass authentication entirely for any 2FA-enabled account, including administrators, by brute-forcing an unthrottled 6-digit TOTP code (no attempt counter, no account lockout, and no `wp_login_failed` firing) and receiving a fully authenticated session cookie via `wp_set_auth_cookie` without ever supplying the account password, resulting in complete site takeover. Exploitation requires only a known `user_id` for an account that has the plugin's 2FA feature enabled.
- CVSS 3.1
- 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-25)
- CWE
- CWE-287
- Published
- Modified
- Record from
- the NVD, synced
References
- https://plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advaipbl-2fa-manager.php#L71
- https://plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advaipbl-main.php#L519
- https://plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advaipbl-main.php#L6875
- https://plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advaipbl-main.php#L6912
- https://plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advaipbl-main.php#L7022