inilerm Advanced IP Blocker Plugin up to 8.13.13 on WordPress 2FA Feature handle_login_action user_id improper authentication

Summaryinfo

A vulnerability has been found in inilerm Advanced IP Blocker Plugin up to 8.13.13 and classified as critical. Affected is the function handle_login_action of the component 2FA Feature. This manipulation of the argument user_id causes improper authentication. This vulnerability is handled as CVE-2026-104732. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in inilerm Advanced IP Blocker Plugin up to 8.13.13. It has been declared as critical. Affected by this vulnerability is the function handle_login_action of the component 2FA Feature. The manipulation of the argument user_id with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at wordfence.com. This vulnerability is known as CVE-2026-104732 since 10/02/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/10/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• inilerm

Name

• Advanced IP Blocker Plugin

Version

• 8.13.0
• 8.13.1
• 8.13.2
• 8.13.3
• 8.13.4
• 8.13.5
• 8.13.6
• 8.13.7
• 8.13.8
• 8.13.9
• 8.13.10
• 8.13.11
• 8.13.12
• 8.13.13

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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