CVE-2025-32063

Executive Summary

CVE-2025-32063 is a misconfiguration vulnerability in the Infotainment ECU manufactured by Bosch, specifically identified in the 2020 Nissan Leaf ZE1. During the startup phase of a specific systemd service, the ECU activates developer features: it disables the firewall and launches an SSH server. This exposes the vehicle’s infotainment system to unauthorized network access, potentially allowing an attacker to connect via SSH, execute arbitrary commands, and pivot to other vehicle networks. The vulnerability has a CVSS score of 6.8 (Medium) and currently has no known patch or public exploit code.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level misconfiguration in an embedded Linux system (systemd service) within a Bosch Infotainment ECU.

CVSS Breakdown & Threat Level

• CVSS Score: 6.8 (Medium)
• Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Local (requires physical or network access to the vehicle’s internal network)
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: Medium. While the CVSS is moderate, the impact is high due to full system compromise. However, exploitation requires access to the vehicle’s internal network (e.g., via OBD-II port or compromised telematics unit).

Deep Dive & Mechanics

The vulnerability resides in a systemd service that runs during the boot sequence of the Infotainment ECU. The service is intended for development or debugging purposes but is incorrectly enabled in production firmware. When the service starts, it executes a script that:

1. Disables the system firewall (e.g., iptables or nftables rules are flushed).
2. Starts the SSH daemon (sshd) with default or weak credentials.

This effectively opens the ECU to remote SSH access from any device on the same network segment (e.g., CAN bus, Ethernet, or Wi-Fi). An attacker with network access can:

• SSH into the ECU using default credentials (often root/root or admin/admin).
• Execute arbitrary commands as root.
• Access sensitive data (e.g., GPS, vehicle logs, user contacts).
• Pivot to other ECUs on the vehicle’s internal network (e.g., CAN bus).

The vulnerability is triggered automatically at every boot, meaning a simple power cycle re-enables the insecure state.

Vulnerable vs. Patched Code

Vulnerable Code (systemd service file):

[Unit]
Description=Developer Mode Service
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/bin/dev_mode.sh
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

Vulnerable Script (/usr/bin/dev_mode.sh):

#!/bin/bash
# Developer mode - enable SSH and disable firewall
systemctl stop firewalld
systemctl disable firewalld
iptables -F
systemctl start sshd
systemctl enable sshd

Patched Code (hypothetical):

[Unit]
Description=Developer Mode Service (Disabled)
ConditionPathExists=!/factory/dev_mode_enabled
After=network.target

[Service]
Type=oneshot
ExecStart=/bin/true
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

The patched version checks for a physical or signed flag (e.g., /factory/dev_mode_enabled) before executing any developer actions. In production, this flag is absent, so the service does nothing.

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• Physical or network access to the vehicle’s internal network (e.g., via OBD-II port, compromised telematics, or Wi-Fi).
• A laptop with SSH client and network scanning tools.

Steps:

1. Scan for SSH: Use Nmap to discover the ECU’s IP address (often on a 192.168.x.x subnet).

   nmap -p 22 192.168.1.0/24
   

2. Connect via SSH: Use default credentials (e.g., root:root).

   ssh root@192.168.1.10
   

3. Post-Exploitation: Once logged in, disable logging, extract data, or pivot to CAN bus.

   # Disable auditd
   systemctl stop auditd
   # Dump GPS data
   cat /var/log/gps.log
   # Access CAN bus
   candump can0
   

Blue Team (Defender)

Detection:

• Monitor for unexpected SSH connections on the vehicle’s network.
• Check for firewall rule changes (e.g., iptables -L showing empty rules).
• Look for systemd service dev_mode.service running at boot.

Hunting:

• Use the Sigma rule below to detect SSH startup events.
• Verify that the firewall is active and SSH is disabled on production ECUs.

Mitigation:

• Apply a firmware update if available.
• If not, manually disable the service via a script or OTA update:

  systemctl mask dev_mode.service
  systemctl stop sshd
  systemctl disable sshd
  systemctl start firewalld
  systemctl enable firewalld
  

Indicators of Compromise (IOCs)

• Network: SSH connections to/from the ECU on port 22.
• Process: sshd running on the ECU.
• File: /usr/bin/dev_mode.sh present and executable.
• Systemd: dev_mode.service enabled and active.
• Firewall: Empty iptables ruleset (output of iptables -L shows no rules).
• Log: Systemd journal entries for dev_mode.service startup.

Detection Engineering

YARA Rule

rule CVE_2025_32063_DevModeScript
{
    meta:
        description = "Detects the developer mode script used in CVE-2025-32063"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-32063"
    strings:
        $s1 = "systemctl stop firewalld" ascii
        $s2 = "iptables -F" ascii
        $s3 = "systemctl start sshd" ascii
        $s4 = "systemctl enable sshd" ascii
    condition:
        all of ($s*)
}

Sigma Rule

title: SSH Service Start via Developer Mode Script
id: 8a9b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects the startup of SSH service via the dev_mode.sh script associated with CVE-2025-32063
author: Valters IT
date: 2025-04-01
logsource:
    product: linux
    service: systemd
detection:
    selection:
        Unit: "dev_mode.service"
        Message: "Started SSH Service"
    condition: selection
falsepositives:
    - Legitimate developer testing on non-production vehicles
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET 22 (msg:"CVE-2025-32063 - SSH Connection to Bosch Infotainment ECU"; flow:to_server; content:"SSH-2.0-OpenSSH"; depth:20; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable service: If physical access is possible, connect to the ECU via a debug interface and run:

   systemctl mask dev_mode.service
   systemctl stop sshd
   systemctl disable sshd
   systemctl start firewalld
   systemctl enable firewalld
   

2. Network segmentation: Ensure the infotainment ECU is isolated from critical vehicle networks (e.g., CAN bus) via a gateway firewall.
3. Monitor for SSH connections: Deploy network monitoring to detect unauthorized SSH traffic.

Long-Term Fix:

• Bosch must release a firmware update that removes the developer mode service or requires a physical jumper/signed certificate to enable it.
• Vehicle manufacturers (e.g., Nissan) should enforce secure boot and signed firmware updates to prevent tampering.

Workaround:

• If patching is not possible, implement an external firewall or IDS on the vehicle’s network to block SSH traffic.

Valters IT
Securing the Connected Vehicle Ecosystem