CVE-2024-47339: WP Mail Catcher Reflected XSS Vulnerability

CVE-2024-47339 Overview

CVE-2024-47339 is a reflected Cross-Site Scripting (XSS) vulnerability in the WP Mail Catcher WordPress plugin developed by JWardee. The flaw affects all versions of wp-mail-catcher up to and including 2.1.9. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers to inject arbitrary JavaScript that executes in a victim's browser. The issue is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation).

Critical Impact

Attackers can execute arbitrary JavaScript in the context of an authenticated WordPress administrator's session, leading to session hijacking, credential theft, and unauthorized administrative actions.

Affected Products

• JWardee WP Mail Catcher plugin for WordPress
• All versions from initial release through 2.1.9
• WordPress sites with the wp-mail-catcher plugin installed and active

Discovery Timeline

• 2024-10-06 - CVE-2024-47339 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2024-47339

Vulnerability Analysis

The vulnerability is a reflected XSS flaw in the WP Mail Catcher plugin. Reflected XSS occurs when an application takes input from an HTTP request and echoes it back into the response without proper sanitization or output encoding. An attacker crafts a malicious URL containing JavaScript payloads in request parameters. When a victim, typically an authenticated WordPress administrator, clicks the link, the payload executes in the browser within the WordPress admin context.

Exploitation requires user interaction, as the victim must click a crafted link or visit an attacker-controlled page. The scope is changed, meaning the injected script can affect resources beyond the vulnerable component, including the broader WordPress administrative interface. Successful exploitation can lead to administrative account compromise across the affected WordPress site.

Root Cause

The plugin processes input parameters from HTTP requests and reflects them into rendered HTML pages without applying proper output encoding or input sanitization. WordPress provides native functions such as esc_html(), esc_attr(), and wp_kses() to safely render user input, but these were not consistently applied to the affected parameter handling in wp-mail-catcher versions up to 2.1.9.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker constructs a URL targeting a vulnerable WP Mail Catcher endpoint with a JavaScript payload embedded in a reflected parameter. The attacker then delivers the link via phishing email, malicious advertisement, or social engineering. When a logged-in WordPress administrator follows the link, the browser renders the page and executes the injected script with the administrator's privileges. The attacker can then exfiltrate session cookies, perform actions on behalf of the administrator, or pivot to deeper site compromise.

No verified public proof-of-concept code is available. See the Patchstack Vulnerability Report for additional technical context.

Detection Methods for CVE-2024-47339

Indicators of Compromise

• Suspicious URL patterns in web server access logs containing JavaScript fragments such as <script>, onerror=, onload=, or URL-encoded equivalents (%3Cscript%3E) targeting wp-mail-catcher endpoints.
• Unexpected outbound requests from administrator browsers to attacker-controlled domains shortly after visiting WordPress admin pages.
• Unauthorized changes to WordPress user accounts, plugins, or content following administrator sessions.

Detection Strategies

• Inspect WordPress access logs for requests to wp-mail-catcher plugin paths containing reflected parameters with HTML or JavaScript metacharacters.
• Deploy a Web Application Firewall (WAF) with rules targeting reflected XSS patterns against WordPress plugin endpoints.
• Use automated vulnerability scanners that fingerprint WordPress plugins and identify the installed version of wp-mail-catcher.

Monitoring Recommendations

• Monitor WordPress administrator session activity for anomalous actions, including unexpected user creation or privilege changes.
• Alert on HTTP requests containing common XSS payload signatures targeting WordPress admin endpoints.
• Track plugin inventory across WordPress instances to identify hosts running vulnerable versions of wp-mail-catcher.

How to Mitigate CVE-2024-47339

Immediate Actions Required

• Identify all WordPress installations with the wp-mail-catcher plugin installed and verify the installed version.
• Deactivate the plugin on any instance running version 2.1.9 or earlier until a patched release is confirmed.
• Educate WordPress administrators to avoid clicking unsolicited links to their own admin interfaces.

Patch Information

At the time of NVD publication, the vulnerability affects WP Mail Catcher through version 2.1.9. Administrators should consult the Patchstack Vulnerability Report and the WordPress plugin repository for the latest fixed release and apply updates as soon as they become available.

Workarounds

• Deactivate and remove the wp-mail-catcher plugin until a patched version is installed.
• Restrict WordPress administrative access to known IP addresses through web server or WAF rules.
• Enforce a Content Security Policy (CSP) header on WordPress admin pages to limit the impact of injected scripts.
• Require administrators to use separate browsers or browser profiles for WordPress management to reduce session compromise risk.