CVE-2024-51688: FraudLabs Pro SMS CSRF Vulnerability

CVE-2024-51688 Overview

CVE-2024-51688 is a Cross-Site Request Forgery (CSRF) vulnerability in the FraudLabs Pro SMS Verification plugin for WordPress. The flaw affects all plugin versions up to and including 1.10.1. An attacker can chain the CSRF weakness with a Stored Cross-Site Scripting (XSS) payload, allowing persistent script injection into the affected WordPress site. Exploitation requires user interaction, typically tricking an authenticated administrator into visiting a malicious page. The issue is tracked under CWE-352 and was published to NVD on November 14, 2024.

Critical Impact
A successful attack stores attacker-controlled JavaScript in the WordPress site, enabling session theft, administrative account takeover, and downstream visitor compromise.

Affected Products

FraudLabs Pro SMS Verification WordPress plugin (fraudlabs-pro-sms-verification)
All versions from initial release through 1.10.1
WordPress sites with the plugin installed and an authenticated administrator session

Discovery Timeline

2024-11-14 - CVE-2024-51688 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2024-51688

Vulnerability Analysis

The vulnerability combines two distinct weaknesses into a single exploit chain. The plugin's administrative endpoints do not validate CSRF tokens (nonces) before processing state-changing requests. The same endpoints also fail to sanitize or encode user-supplied input before storing it and rendering it back in administrative pages.

An attacker hosts a malicious page containing a forged request targeting the plugin's settings handler. When an authenticated WordPress administrator visits that page, the browser submits the forged request using the administrator's session cookies. The injected payload is then persisted in the plugin's configuration and executed in the browser of any subsequent administrator who views the affected page.

Root Cause

The root cause is the absence of anti-CSRF token validation on plugin form handlers, compounded by insufficient output encoding on stored settings values. WordPress provides wp_nonce_field() and check_admin_referer() primitives to mitigate CSRF, but these controls are not enforced on the vulnerable endpoints in versions up to 1.10.1. Stored input is rendered into admin pages without esc_attr() or esc_html() encoding.

Attack Vector

Exploitation occurs over the network and requires user interaction from a privileged WordPress user. The attacker delivers a crafted link or embeds an auto-submitting form on an attacker-controlled site. Because no nonce is validated, the malicious request is accepted as legitimate, and the XSS payload becomes persistent in the plugin's stored configuration. The scope changes once script execution moves into the WordPress admin context. Refer to the Patchstack WordPress Vulnerability Report for additional technical context.

Detection Methods for CVE-2024-51688

Indicators of Compromise

Unexpected <script>, onerror, or onload attributes appearing in FraudLabs Pro SMS Verification plugin settings stored in the wp_options table
Administrator browsers issuing outbound requests to unknown domains immediately after visiting plugin configuration pages
New WordPress administrator accounts or modified user roles created without a corresponding audit trail entry

Detection Strategies

Inspect plugin configuration values in the database for HTML or JavaScript syntax that should not appear in legitimate settings fields
Review web server access logs for POST requests to plugin admin endpoints that lack a valid _wpnonce parameter or carry a suspicious Referer header
Monitor WordPress audit logs for plugin setting changes that do not correlate with intentional administrator activity

Monitoring Recommendations

Enable a Web Application Firewall (WAF) ruleset that flags requests to /wp-admin/ endpoints from external referrers
Alert on administrator browser sessions generating anomalous outbound traffic shortly after authenticating to /wp-admin/
Track plugin version inventory across hosted WordPress sites and alert when fraudlabs-pro-sms-verification is present at version 1.10.1 or earlier

How to Mitigate CVE-2024-51688

Immediate Actions Required

Update the FraudLabs Pro SMS Verification plugin to a version newer than 1.10.1 as soon as a fixed release is available from the vendor
If no patched release is available, deactivate and remove the plugin from affected WordPress installations
Audit plugin settings and remove any unexpected HTML or JavaScript content from stored configuration values
Force a password reset for all WordPress administrator accounts that may have visited untrusted sites while authenticated

Patch Information

Review the Patchstack advisory for the latest fixed version information. The advisory identifies version 1.10.1 and below as vulnerable. Apply the vendor patch through the WordPress plugin manager once published, and verify the installed version after the update.

Workarounds

Restrict access to /wp-admin/ by IP allowlist at the web server or WAF layer to reduce CSRF exposure
Deploy a WAF rule that blocks POST requests to plugin endpoints lacking a valid same-origin Referer and WordPress nonce
Train administrators to log out of WordPress sessions before browsing untrusted sites and to use a dedicated browser profile for admin tasks
Enforce a Content Security Policy (CSP) on /wp-admin/ that disallows inline scripts to limit the impact of stored XSS

bash

# Example NGINX snippet to restrict wp-admin access by IP
location ^~ /wp-admin/ {
    allow 203.0.113.0/24;   # trusted admin network
    deny all;
    try_files $uri $uri/ /index.php?$args;
}