CVE-2024-13226 Overview
CVE-2024-13226 is a Reflected Cross-Site Scripting (XSS) vulnerability in the A5 Custom Login Page WordPress plugin developed by Tepelstreel. The flaw affects all versions through 2.8.1. The plugin fails to sanitise and escape a user-supplied parameter before reflecting it back into the rendered page. An attacker can craft a malicious URL that executes arbitrary JavaScript in the victim's browser session. The vulnerability targets high-privilege users such as administrators through social engineering. The issue is tracked under CWE-79 and requires user interaction to trigger.
Critical Impact
Successful exploitation lets attackers hijack administrator sessions, inject malicious content, or perform actions in the context of authenticated WordPress users.
Affected Products
- Tepelstreel A5 Custom Login Page WordPress plugin versions up to and including 2.8.1
- WordPress sites running the plugin with administrative users
- Any deployment where administrators can be lured into clicking crafted links
Discovery Timeline
- 2025-01-31 - CVE-2024-13226 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-13226
Vulnerability Analysis
The A5 Custom Login Page plugin accepts an input parameter and echoes its value directly into HTML output. Because the plugin performs no sanitisation or output escaping, an attacker can inject arbitrary HTML and JavaScript into the response. The payload executes when a victim loads the crafted URL in an authenticated browser session. This is a Reflected XSS pattern classified under CWE-79. The scope change indicated by the vulnerability metadata reflects that injected script can affect resources beyond the vulnerable component, such as the WordPress administrative interface.
Root Cause
The root cause is missing input validation and output encoding in the plugin's request handling code. WordPress provides functions such as esc_html(), esc_attr(), and sanitize_text_field() for safe output, but the plugin does not apply these to the affected parameter. User-controlled data flows directly from the HTTP request into the HTML response without transformation.
Attack Vector
An attacker crafts a URL pointing to the vulnerable plugin endpoint with a JavaScript payload embedded in the reflected parameter. The attacker delivers the URL through phishing email, forum posts, or malicious advertising. When a logged-in WordPress administrator clicks the link, the browser executes the injected script under the origin of the WordPress site. The script can steal session cookies, submit forms via CSRF chaining, create rogue administrator accounts, or install malicious plugins. See the WPScan Vulnerability Report for further technical details.
Detection Methods for CVE-2024-13226
Indicators of Compromise
- Web server access logs containing URL parameters with encoded <script>, onerror=, or javascript: payloads targeting A5 Custom Login Page endpoints
- Unexpected creation of new WordPress administrator accounts following administrator browsing sessions
- Outbound requests from administrator browsers to attacker-controlled domains shortly after visiting crafted links
Detection Strategies
- Deploy a web application firewall (WAF) with rules that flag reflected XSS patterns in query strings and POST bodies
- Review WordPress access logs for requests to plugin endpoints containing HTML entities, script tags, or event handler attributes
- Correlate administrator login events with subsequent privileged actions to detect anomalous behavior chains
Monitoring Recommendations
- Enable Content Security Policy (CSP) reporting to capture script execution violations on WordPress admin pages
- Monitor plugin installation, user creation, and role modification events in the WordPress audit log
- Alert on administrator sessions originating from unfamiliar IP addresses or user agents
How to Mitigate CVE-2024-13226
Immediate Actions Required
- Deactivate the A5 Custom Login Page plugin until a patched release is confirmed and installed
- Invalidate all active administrator sessions and require password resets for privileged users
- Audit WordPress user accounts and installed plugins for unauthorised additions
Patch Information
At the time of NVD publication, no fixed version was identified beyond 2.8.1. Administrators should monitor the WPScan Vulnerability Report and the WordPress plugin repository for vendor updates. If no patch is available, replace the plugin with an actively maintained alternative.
Workarounds
- Restrict access to the WordPress administrative interface using IP allowlists at the web server or WAF layer
- Enforce a strict Content Security Policy that blocks inline scripts and untrusted external script sources
- Train administrators to avoid clicking untrusted links while authenticated to WordPress
- Enable multi-factor authentication (MFA) for all WordPress administrator accounts to limit session hijacking impact
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.