CVE-2025-44614

Executive Summary

CVE-2025-44614 exposes a critical security flaw in the Tinxy WiFi Lock Controller v1 RF, where users' sensitive information—including credentials and mobile phone numbers—is stored in plaintext. This vulnerability allows any attacker with local or network access to the device (or its associated storage) to harvest credentials and personal data, leading to unauthorized access, identity theft, or physical lock compromise. The vendor has not released a patch, and no official advisory or fix is available at this time.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a hardware/firmware issue in the Tinxy WiFi Lock Controller v1 RF device.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official vector assigned; estimated high severity)
• Attack Vector (AV): Local/Adjacent Network (likely AV:L or AV:A)
• Attack Complexity (AC): Low (AC:L)
• Privileges Required (PR): None (PR:N)
• User Interaction (UI): None (UI:N)
• Scope (S): Unchanged (S:U)
• Confidentiality (C): High (C:H)
• Integrity (I): None (I:N)
• Availability (A): None (A:N)
• Estimated CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Threat Level: High – Plaintext storage of credentials enables immediate credential theft and lateral movement.

Deep Dive & Mechanics

The Tinxy WiFi Lock Controller v1 RF stores user credentials (WiFi passwords, lock PINs, mobile numbers) in plaintext within its firmware or configuration files. This is a classic violation of CWE-312. The data is likely stored in a JSON, XML, or binary configuration file accessible via:

• Physical UART/JTAG interfaces
• Network file shares (if enabled)
• Backup/export functions
• Firmware extraction

Attackers can extract this data without authentication if they gain local access (e.g., via a compromised mobile app, physical access to the device, or network sniffing of unencrypted backups). The plaintext storage means no decryption is needed, making exploitation trivial.

Vulnerable vs. Patched Code

Vulnerable Code (Example – Tinxy firmware config file):

{
  "wifi_ssid": "HomeNetwork",
  "wifi_password": "MyPlainTextPassword123",
  "lock_pin": "1234",
  "owner_phone": "+1234567890"
}

Patched Code (Hypothetical – should use encryption):

{
  "wifi_ssid": "HomeNetwork",
  "wifi_password": "AES256_ENCRYPTED_BASE64_STRING",
  "lock_pin": "HASHED_PIN",
  "owner_phone": "ENCRYPTED_PHONE"
}

No official patch exists. The vendor must implement encryption at rest (e.g., AES-256-GCM) and hashing for PINs.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• Physical access to the Tinxy WiFi Lock Controller v1 RF device
• OR network access to its management interface (if exposed)
• OR ability to extract firmware via UART/JTAG

Steps:

1. Extract firmware using a tool like binwalk:

   binwalk -e firmware.bin
   

2. Search for plaintext credentials in extracted files:

   grep -r "password\|pin\|phone" extracted_fs/
   

3. Dump configuration via serial console (if accessible):

   screen /dev/ttyUSB0 115200
   # Send command: cat /config.json
   

4. Exploit – Copy credentials and use them to access the lock or owner's WiFi.

Example output:

Found: /config.json
  "wifi_password": "MyPlainTextPassword123"
  "lock_pin": "1234"

Blue Team (Defense & Detection)

Defensive Measures:

• Isolate IoT devices on a separate VLAN with strict firewall rules.
• Disable physical debug interfaces (UART/JTAG) if possible.
• Monitor for unauthorized firmware extraction attempts.
• Use network segmentation to prevent lateral movement from compromised devices.

Detection:

• Monitor for unusual serial port activity (e.g., screen or minicom connections).
• Alert on mass file reads from the device's filesystem.
• Deploy honeytokens (fake credentials) in config files to detect extraction.

Indicators of Compromise (IOCs)

• File Hashes (firmware): Unknown (vendor-specific)
• Network Traffic: Unencrypted HTTP/HTTPS traffic containing plaintext credentials (e.g., POST requests with password field)
• Processes: cat, grep, strings running on the device
• Logs: Serial console logs showing cat /config.json or similar commands
• Physical: UART/JTAG connections detected via voltage or signal monitoring

Detection Engineering

YARA Rule

rule Tinxy_Plaintext_Credentials {
    meta:
        description = "Detects plaintext credentials in Tinxy WiFi Lock Controller config files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-44614"
    strings:
        $s1 = "wifi_password" ascii wide nocase
        $s2 = "lock_pin" ascii wide nocase
        $s3 = "owner_phone" ascii wide nocase
        $s4 = /"password"\s*:\s*"[^"]+"/ ascii
    condition:
        any of ($s1, $s2, $s3) or $s4
}

Sigma Rule

title: Tinxy WiFi Lock Controller Plaintext Credentials
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects access to plaintext credential files on Tinxy devices
author: Valters IT
date: 2025/04/10
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/cat'
        CommandLine|contains: 'config.json'
    condition: selection
falsepositives:
    - Legitimate admin access
level: high

Suricata Rule

alert tcp any any -> any any (msg:"Tinxy WiFi Lock - Plaintext Credential Exfiltration"; flow:to_server; content:"wifi_password"; nocase; content:"lock_pin"; nocase; distance:0; within:100; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the Tinxy device on a separate VLAN with no internet access.
2. Change all credentials stored on the device (WiFi passwords, lock PINs).
3. Disable physical debug interfaces (UART/JTAG) if accessible.
4. Monitor for unauthorized access attempts.

Long-Term Fix:

• Vendor must release a firmware update that encrypts all sensitive data at rest using AES-256-GCM and hashes PINs with bcrypt.
• Users should replace the device if no patch is provided.

Workaround:

• Use a separate, dedicated WiFi network for the lock with a unique password.
• Do not store sensitive phone numbers in the device configuration.

Valters IT
Securing IoT, One Vulnerability at a Time