Advanced IP Blocker <= 8.13.13 - Unauthenticated Authentication Bypass via Missing Step-1 Binding to 2FA Login Handler

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-104732
StatePUBLISHED
AssignerWordfence
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-10 04:18:08 UTC
Updated2026-10-13 13:30:21 UTC
DescriptionThe 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.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.004730000 probability, percentile 0.391040000 (date 2026-10-12)

Problem Types: CWE-287 | CWE-287 CWE-287 Improper Authentication

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Inilerm Advanced IP Blocker affected 8.13.13 semver Not specified

References

ReferenceSourceLinkTags
plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advai... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advai... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advai... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advai... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/advanced-ip-blocker/tags/8.13.13/includes/class-advai... [email protected] plugins.trac.wordpress.org
www.wordfence.com/threat-intel/vulnerabilities/id/d080845b-6814-4b10-a3ab-1f5aa... [email protected] www.wordfence.com
plugins.trac.wordpress.org/changeset/3725139/advanced-ip-blocker/trunk/includes/class-ad... [email protected] plugins.trac.wordpress.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Wordfence PRISM (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-10-02T13:19:16.000ZVendor Notified
CNA2026-10-09T15:13:42.000ZDisclosed

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