CVE-2025-2349

Executive Summary

CVE-2025-2349 identifies a critical security flaw in the IROAD Dash Cam FX2 firmware up to version 20250308. The vulnerability resides in the /etc/passwd file, where password hashes are stored with insufficient computational effort (CWE-916). This allows an attacker with local network access to extract and crack password hashes offline, potentially gaining unauthorized access to the device. The attack complexity is high, but the exploit has been publicly disclosed, increasing the risk of targeted attacks. No official patch is available at this time.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby ecosystems. It is a firmware-level issue in an embedded IoT device (IROAD Dash Cam FX2). Supply chain risks include the distribution of unpatched firmware images and the lack of secure update mechanisms.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Adjacent Network (AV:A) – Requires local network access.
• Attack Complexity (AC): High (AC:H) – Exploitation is difficult due to network proximity and hash cracking requirements.
• Privileges Required (PR): None (PR:N)
• User Interaction (UI): None (UI:N)
• Scope (S): Unchanged (S:U)
• Confidentiality (C): High (C:H) – Password hashes are exposed.
• Integrity (I): None (I:N)
• Availability (A): None (A:N)
• Base Score: 5.3 (Medium)

Threat Level: Medium. The vulnerability requires local network access and high attack complexity, but the public exploit disclosure and lack of patch elevate the risk for targeted attacks.

Deep Dive & Mechanics

The IROAD Dash Cam FX2 stores user password hashes in the /etc/passwd file. The vulnerability arises because the hashing algorithm used has insufficient computational effort (e.g., weak hash like MD5 or DES-based crypt). This makes the hashes susceptible to offline brute-force or dictionary attacks.

Attack Flow:

1. Reconnaissance: Attacker scans the local network for IROAD FX2 devices (e.g., using Shodan dorks or network scanning).
2. Access: Attacker gains access to the device's filesystem via an exposed service (e.g., Telnet, FTP, or web interface) or by exploiting another vulnerability.
3. Extraction: Attacker retrieves the /etc/passwd file.
4. Cracking: Attacker uses tools like John the Ripper or Hashcat to crack the weak password hashes.
5. Privilege Escalation: With a cracked password, the attacker gains root or user-level access to the device.

Root Cause: The use of a weak password hashing algorithm (likely DES-based crypt or MD5) that lacks computational hardness (e.g., no salt or low iteration count).

Vulnerable vs. Patched Code

Vulnerable Code (IROAD FX2 firmware <= 20250308): The /etc/passwd file contains entries like:

root:$1$salt$hash:0:0:root:/root:/bin/sh

Where $1$ indicates MD5-based crypt, which is computationally weak.

Patched Code (Hypothetical): A secure implementation would use bcrypt, scrypt, or PBKDF2 with a high cost factor:

root:$2y$10$saltroundshash:0:0:root:/root:/bin/sh

Where $2y$10$ indicates bcrypt with cost factor 10.

Note: No official patch is available. The above is a recommended fix.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Local network access to the IROAD FX2 device.
• Ability to extract the /etc/passwd file (e.g., via Telnet, FTP, or web shell).

Steps:

1. Scan for devices:

   nmap -p 23,21,80 192.168.1.0/24
   

2. Extract /etc/passwd:

   telnet 192.168.1.100
   # Login with default credentials (if known) or exploit another vulnerability
   cat /etc/passwd
   

3. Crack hashes:

   john --format=md5crypt passwd.txt
   # or
   hashcat -m 500 -a 0 passwd.txt rockyou.txt
   

Exploit Code (Conceptual):

import requests

# Example: Exploit via web interface to download /etc/passwd
url = "http://192.168.1.100/cgi-bin/download?file=/etc/passwd"
response = requests.get(url)
if response.status_code == 200:
    with open("passwd.txt", "wb") as f:
        f.write(response.content)
    print("Password file extracted.")

Blue Team (Defensive)

Detection:

• Monitor for unauthorized access to /etc/passwd via file integrity monitoring (FIM).
• Alert on failed login attempts or unusual network traffic to port 23/21/80.

Honeypot:

• Deploy a fake IROAD FX2 device with a weak password hash to lure attackers.

Lab Setup:

• Use a virtualized IROAD FX2 firmware (e.g., via QEMU) for testing.
• Simulate the attack in a controlled environment.

Indicators of Compromise (IOCs)

• File Hash (SHA256): e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 (example, replace with actual hash of vulnerable firmware)
• Network Signatures:
  • Telnet connections to port 23 from unknown IPs.
  • HTTP GET requests to /cgi-bin/download?file=/etc/passwd.
• Process Anomalies:
  • Unusual cat or cp commands on /etc/passwd.
• Log Entries:
  • Failed password for root in /var/log/auth.log.

Detection Engineering

YARA Rule

rule CVE_2025_2349_IROAD_Passwd_Hash
{
    meta:
        description = "Detects weak password hashes in IROAD FX2 /etc/passwd"
        author = "Valters IT"
        date = "2025-03-09"
        hash = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
    strings:
        $md5crypt = /\$1\$[A-Za-z0-9\/\.]{8}\$[A-Za-z0-9\/\.]{22}/
        $descrypt = /[A-Za-z0-9\/\.]{13}/
    condition:
        any of them
}

Sigma Rule

title: IROAD FX2 Weak Password Hash Extraction
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to extract /etc/passwd from IROAD FX2 devices
author: Valters IT
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/cat'
        CommandLine|contains: '/etc/passwd'
    condition: selection
falsepositives:
    - Legitimate administrative access
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET 23 (msg:"IROAD FX2 Telnet Password Hash Extraction"; flow:to_server,established; content:"cat /etc/passwd"; nocase; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected devices: Place IROAD FX2 dash cams on a separate VLAN with strict access controls.
2. Change default passwords: Use strong, unique passwords for all device accounts.
3. Disable unnecessary services: Turn off Telnet, FTP, or any remote access if not required.

Long-term Fix:

• Firmware update: Await an official patch from IROAD that implements strong password hashing (e.g., bcrypt).
• Custom hardening: If possible, replace the /etc/passwd file with a version using bcrypt hashes (requires root access).

Workaround:

• Use network segmentation and firewall rules to restrict access to the device's management interfaces.

Valters IT