CVE-2024-2848: WordPress Responsive Theme XSS Vulnerability

CVE-2024-2848 Overview

CVE-2024-2848 affects the Responsive theme for WordPress through version 5.0.2. The vulnerability stems from a missing capability check on the save_footer_text_callback function. Unauthenticated attackers can inject arbitrary HTML content into the site's footer without any authorization. This issue is classified under [CWE-862] Missing Authorization. The flaw enables remote modification of site content over the network without user interaction or privileges.

Critical Impact
Unauthenticated attackers can inject arbitrary HTML into the WordPress site footer, enabling content defacement, phishing redirects, and malicious script delivery to all site visitors.

Affected Products

Responsive theme for WordPress, all versions up to and including 5.0.2
WordPress sites using the vulnerable save_footer_text_callback function
Any deployment where the Responsive theme is active and accessible from the network

Discovery Timeline

2024-03-29 - CVE-2024-2848 published to NVD
2024-04-22 - Public disclosure via Openwall OSS Security mailing list
2026-04-15 - Last updated in NVD database

Technical Details for CVE-2024-2848

Vulnerability Analysis

The Responsive theme exposes an AJAX handler tied to the save_footer_text_callback function. This handler accepts footer text updates but fails to verify whether the requesting user holds the appropriate WordPress capability. Without a current_user_can() check or a nonce validation tied to an authenticated administrative session, the endpoint accepts requests from any source.

An attacker sends a crafted HTTP request to the WordPress AJAX endpoint with arbitrary footer content. The theme persists this content to the database and renders it on every page load. The injected HTML executes in the browser context of every site visitor, including administrators.

This Broken Access Control flaw enables content tampering across the entire site. Attackers can plant phishing links, deceptive notices, or redirect markup. The impact extends beyond defacement when injected markup is leveraged for downstream attacks.

Root Cause

The root cause is a missing authorization check ([CWE-862]) inside save_footer_text_callback. The function processes incoming POST data and writes to theme options without confirming the caller's privilege level. WordPress requires developers to gate administrative actions with capability checks such as current_user_can('manage_options') and nonce verification via check_ajax_referer(). Both safeguards are absent in vulnerable versions.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker identifies a WordPress site running the Responsive theme version 5.0.2 or earlier. The attacker then issues a POST request to the site's admin-ajax.php endpoint, targeting the registered action for save_footer_text_callback. The payload contains attacker-controlled HTML that is stored and served to every visitor.

The vulnerability mechanism is described in the Wordfence Vulnerability Report and the corresponding WordPress Theme Changeset that introduces the fix.

Detection Methods for CVE-2024-2848

Indicators of Compromise

Unexpected HTML, <script>, or <iframe> tags appearing in the WordPress site footer
POST requests to /wp-admin/admin-ajax.php referencing the footer text save action from unauthenticated sources
Database modifications to theme options storing footer text from non-administrator sessions
Outbound redirects or external resource loads originating from footer markup

Detection Strategies

Monitor web server access logs for POST requests to admin-ajax.php lacking valid authentication cookies
Compare rendered footer HTML against a known-good baseline using file integrity or content monitoring
Audit the wp_options table for unexpected changes to Responsive theme settings
Deploy a Web Application Firewall (WAF) rule blocking unauthenticated calls to the vulnerable AJAX action

Monitoring Recommendations

Enable WordPress audit logging to capture changes to theme options and the user context performing them
Alert on any HTML or JavaScript tags introduced into footer fields, which should contain plain text in normal use
Track HTTP referer and origin headers on AJAX requests to identify off-site attack traffic

How to Mitigate CVE-2024-2848

Immediate Actions Required

Update the Responsive theme to a version later than 5.0.2 that includes the capability check fix
Audit the current footer content for injected HTML or scripts and restore from a clean backup if tampering is found
Review WordPress user accounts and session activity for signs of follow-on compromise
Apply WAF rules to block unauthenticated requests to the vulnerable AJAX endpoint until patching is complete

Patch Information

The vendor addressed the issue by adding a capability check to save_footer_text_callback. The fix is documented in the WordPress Theme Changeset and tracked in the Wordfence Vulnerability Report. Site administrators should update through the WordPress theme management interface to the latest available version.

Workarounds

Switch to an alternative WordPress theme until the Responsive theme is updated
Deploy WAF rules denying POST requests to admin-ajax.php when the action parameter matches the vulnerable footer save handler and the request lacks a valid administrator session
Restrict access to /wp-admin/admin-ajax.php from untrusted networks at the reverse proxy layer where feasible

bash

# Example WAF rule concept (ModSecurity-style) blocking unauthenticated footer save
SecRule REQUEST_URI "@endsWith /wp-admin/admin-ajax.php" \
  "chain,deny,status:403,id:1002848,msg:'Block CVE-2024-2848 footer save'"
  SecRule ARGS:action "@rx save_footer_text" "chain"
    SecRule &REQUEST_COOKIES:/wordpress_logged_in_/ "@eq 0"