CVE-2024-49239: Add Categories Post Footer XSS Vulnerability

CVE-2024-49239 Overview

CVE-2024-49239 is a reflected Cross-Site Scripting (XSS) vulnerability in the Add Categories Post Footer WordPress plugin by nikhilvaghela. The flaw affects all versions up to and including 2.2.2. The plugin fails to properly neutralize user-supplied input before reflecting it in web page output, allowing attackers to inject arbitrary JavaScript that executes in a victim's browser. Exploitation requires user interaction, typically through a crafted link. Successful attacks can lead to session token theft, credential harvesting, or unauthorized actions performed in the context of the victim's WordPress session. The vulnerability is tracked under CWE-79.

Critical Impact
Attackers can execute arbitrary JavaScript in the browser of any user who clicks a crafted link, potentially compromising authenticated WordPress sessions and enabling further site takeover.

Affected Products

Nikhilvaghela Add Categories Post Footer plugin for WordPress
All versions from initial release through 2.2.2
WordPress sites with the plugin installed and activated

Discovery Timeline

2024-10-18 - CVE-2024-49239 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-49239

Vulnerability Analysis

The vulnerability is a reflected Cross-Site Scripting (XSS) issue in the Add Categories Post Footer plugin. The plugin accepts input from HTTP request parameters and reflects that data into the rendered HTML response without proper output encoding or sanitization. Because the reflected content is rendered as part of the page markup, an attacker-controlled payload executes as JavaScript in the victim's browser under the origin of the vulnerable WordPress site.

The vulnerability requires user interaction: a victim must click a maliciously crafted URL or submit a manipulated form. When exploited against an authenticated administrator, an attacker can perform actions such as creating new admin accounts, injecting persistent backdoors into plugin or theme files, or exfiltrating session cookies. The scope changes because the injected script runs in the WordPress origin, expanding impact beyond the initially requested resource.

Root Cause

The root cause is improper neutralization of input during web page generation, classified as CWE-79. The plugin does not apply WordPress escaping functions such as esc_html(), esc_attr(), or wp_kses() to user-controlled input before echoing it into the response. This omission allows raw HTML and JavaScript to be rendered by the browser.

Attack Vector

Exploitation is performed remotely over the network without authentication. An attacker crafts a URL containing a JavaScript payload targeting the vulnerable parameter and delivers it to a victim through phishing, forum posts, or social engineering. When the target clicks the link, the payload is reflected in the response and executed by the browser. No prior credentials are required from the attacker, though the victim must be tricked into visiting the malicious link.

Because verified proof-of-concept code is not publicly listed for this CVE, refer to the Patchstack advisory for technical details on the affected parameter and payload structure.

Detection Methods for CVE-2024-49239

Indicators of Compromise

HTTP request logs containing URL parameters with encoded <script>, javascript:, onerror=, or onload= payloads targeting plugin endpoints
Unexpected outbound requests from administrator browsers to attacker-controlled domains shortly after clicking external links
Creation of new administrator accounts or unauthorized modifications to plugin and theme files following a suspicious click event
Referrer headers from unfamiliar domains preceding WordPress admin actions

Detection Strategies

Inspect web server access logs for requests to plugin URLs containing HTML tags, JavaScript event handlers, or URL-encoded angle brackets (%3C, %3E)
Deploy a Web Application Firewall (WAF) with rules that identify reflected XSS payloads in query strings and POST bodies
Correlate browser telemetry with WordPress admin activity to identify script-driven privilege changes
Use file integrity monitoring on wp-content/plugins/ and wp-content/themes/ directories to detect unauthorized modifications

Monitoring Recommendations

Enable verbose logging on the WordPress site and forward logs to a centralized SIEM for pattern analysis
Monitor administrator account creation and role changes in the wp_users and wp_usermeta tables
Alert on repeated 200 responses to plugin endpoints containing suspicious query parameter content
Track outbound HTTP requests from admin sessions to unrecognized external destinations

How to Mitigate CVE-2024-49239

Immediate Actions Required

Update the Add Categories Post Footer plugin to a version newer than 2.2.2 once the vendor publishes a fix
Deactivate and remove the plugin if a patched version is not available and the functionality is not essential
Audit WordPress administrator accounts and remove any unrecognized users
Force password resets for all privileged accounts and rotate any exposed API keys or session tokens

Patch Information

At the time of NVD publication, no fixed version has been confirmed in the referenced advisory. Consult the Patchstack advisory for the plugin for the latest patch status. Apply the vendor update as soon as it becomes available.

Workarounds

Deploy a WAF rule to block requests containing script tags or event-handler attributes in query parameters targeting the plugin
Implement a strict Content Security Policy (CSP) header that disallows inline scripts and restricts script sources to trusted origins
Restrict access to WordPress admin pages by source IP address using web server or firewall rules
Train administrators to avoid clicking untrusted links while authenticated to the WordPress dashboard

bash

# Example nginx configuration to add a restrictive Content Security Policy
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self';" always;
add_header X-XSS-Protection "1; mode=block" always;
add_header X-Content-Type-Options "nosniff" always;