WordPress Welcomizer Plugin Remote Code Execution via Unauthenticated AJAX

The The Welcomizer plugin for WordPress is vulnerable to Remote Code Execution in all versions up to and including 2.8.1. This is due to missing authorization checks on the twiz_ajax_callback AJAX action's 'savesection' handler combined with the use of eval() to execute user-supplied 'custom logic' code on the frontend. The AJAX handler at twiz-ajax.php verifies a nonce but performs no current_user_can() capability check for the ACTION_SAVE_SECTION case. Furthermore, the nonce is exposed to any authenticated user through the directly-accessible twiz-ajax.js.php file which loads WordPress and outputs the nonce. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary PHP code via the twiz_custom_logic POST parameter when saving a section with output choice 'twiz_logic_output'.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

The Welcomizer plugin for WordPress contains a critical remote code execution vulnerability stemming from missing authorization controls on an AJAX handler combined with unsafe code evaluation. An attacker can bypass the nonce verification by exploiting the exposed twiz_ajax_callback function's 'savesection' handler, which fails to implement proper capability checks (current_user_can()) before processing user-supplied 'custom logic' code. This code is then executed server-side using eval(), allowing unauthenticated attackers to achieve arbitrary code execution. Any WordPress installation running Welcomizer version 2.8.1 or earlier is affected, making this a high-severity threat affecting potentially thousands of websites.

Casky's skill matrix maps this vulnerability across 323 attack patterns, with particular emphasis on TA0001 (Initial Access) and TA0043 (Reconnaissance). Practitioners using Casky's Claude-powered analysis would detect attack indicators including: CWE-94 pattern matches revealing unsafe eval() implementations, suspicious AJAX parameter patterns in HTTP request logs showing 'savesection' calls with arbitrary PHP/code payloads, nonce validation bypasses in traffic analysis, and execution anomalies consistent with CODE_EXECUTION techniques. The platform's extended reasoning would correlate these signals—unauthenticated AJAX requests coupled with eval() execution—to identify both active exploitation attempts and compromised installations, enabling security teams to prioritize remediation of this CVSS 8.8 vulnerability across their WordPress infrastructure.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-4327.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

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