CVE-2025-32060

Executive Summary

CVE-2025-32060 is a high-severity vulnerability affecting the Nissan Leaf ZE1 (2020 model) infotainment system. The core issue is the absence of kernel module signature verification, allowing an attacker with root-level command execution to load arbitrary, unsigned kernel modules. This flaw enables privilege escalation from root to full kernel control, leading to complete system compromise. The vulnerability is currently unpatched, and no public proof-of-concept (PoC) or exploit code has been released. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the risk is significant for targeted attacks against Nissan vehicles.

CVSS Breakdown & Threat Level

• CVSS Score: 6.7 (Medium)
• Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Local (requires physical or remote access to the vehicle’s infotainment system)
• Attack Complexity: Low
• Privileges Required: High (root access needed)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: High for targeted attacks. The vulnerability is a critical escalation path once initial root access is achieved.

Deep Dive & Mechanics

The Nissan Leaf ZE1 infotainment system runs a Linux-based operating system. The kernel is configured without module signature verification, meaning any kernel module (.ko file) can be loaded via insmod or modprobe as long as the attacker has root privileges.

Attack Chain:

1. Initial Access: The attacker exploits another vulnerability (e.g., a buffer overflow in the infotainment web interface, a malicious USB device, or a compromised OTA update) to gain a root shell.
2. Privilege Escalation: With root access, the attacker loads a custom kernel module (e.g., a rootkit, keylogger, or backdoor) that executes in kernel space.
3. Persistence & Control: The kernel module can hide processes, intercept system calls, or provide remote access, giving the attacker full control over the vehicle’s systems (e.g., CAN bus, telematics, infotainment).

Root Cause: The kernel configuration lacks CONFIG_MODULE_SIG_FORCE or CONFIG_MODULE_SIG_ALL, which would enforce signature verification for all loaded modules.

Vulnerable vs. Patched Code

Vulnerable System (Nissan Leaf ZE1 2020):

• Kernel configuration: CONFIG_MODULE_SIG=n or CONFIG_MODULE_SIG_FORCE=n
• No signature check on module load.

Patched System (Hypothetical):

• Kernel configuration: CONFIG_MODULE_SIG=y and CONFIG_MODULE_SIG_FORCE=y
• Modules must be signed with a trusted key before loading.

Example of vulnerable behavior:

# On vulnerable system (root shell)
insmod /tmp/malicious.ko  # Succeeds without error

Example of patched behavior:

# On patched system (root shell)
insmod /tmp/malicious.ko  # Fails with "Required key not available"

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Root access on the Nissan Leaf ZE1 infotainment system.
• Ability to transfer files (e.g., via USB, SSH, or network).

Steps:

1. Develop a malicious kernel module (e.g., a simple rootkit that hides a backdoor process).

   // malicious.c
   #include <linux/module.h>
   #include <linux/kernel.h>
   #include <linux/init.h>
   
   static int __init evil_init(void) {
       printk(KERN_INFO "Malicious module loaded!\n");
       // Add rootkit functionality here (e.g., syscall hooking)
       return 0;
   }
   
   static void __exit evil_exit(void) {
       printk(KERN_INFO "Malicious module unloaded.\n");
   }
   
   module_init(evil_init);
   module_exit(evil_exit);
   MODULE_LICENSE("GPL");
   

2. Compile the module for the target kernel version (use the same kernel headers as the infotainment system).

   make -C /lib/modules/$(uname -r)/build M=$(pwd) modules
   

3. Transfer the module to the target (e.g., via USB or SCP).
4. Load the module with root privileges.

   insmod malicious.ko
   

5. Verify the module is loaded.

   lsmod | grep malicious
   

Blue Team (Defense & Detection)

Detection Steps:

1. Monitor kernel module loading using auditd or systemtap.

   auditctl -w /sbin/insmod -p x -k kernel_module_load
   auditctl -w /sbin/modprobe -p x -k kernel_module_load
   

2. Check for unsigned modules by examining /proc/modules and comparing against a known-good list.
3. Enable kernel module signing if possible (requires kernel recompilation).
4. Restrict root access via mandatory access controls (e.g., SELinux, AppArmor).

Lab Setup:

• Use a QEMU emulation of the Nissan Leaf ZE1 infotainment system (if available) or a generic ARM Linux system with the same kernel version.
• Simulate the attack by loading a benign test module.

Indicators of Compromise (IOCs)

• File Hashes: Unknown (no public PoC)
• Process Names: insmod, modprobe (legitimate but suspicious if unexpected)
• Kernel Modules: Any .ko file not in the original firmware image.
• Network Connections: Unexpected outbound connections from the infotainment system (e.g., to a C2 server).
• System Logs: dmesg output showing "Malicious module loaded" or similar custom messages.
• Audit Logs: ausearch -k kernel_module_load showing unauthorized module loads.

Detection Engineering

YARA Rule

rule CVE_2025_32060_Kernel_Module_Load {
    meta:
        description = "Detects attempts to load unsigned kernel modules on Nissan Leaf ZE1"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-32060"
    strings:
        $insmod = "insmod" nocase
        $modprobe = "modprobe" nocase
        $ko_ext = ".ko" nocase
    condition:
        ($insmod or $modprobe) and $ko_ext
}

Sigma Rule

title: Unsigned Kernel Module Load on Nissan Infotainment
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects execution of insmod or modprobe with a .ko file, indicating potential exploitation of CVE-2025-32060
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith:
            - '/insmod'
            - '/modprobe'
        CommandLine|contains: '.ko'
    condition: selection
falsepositives:
    - Legitimate kernel module updates by authorized personnel
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-32060 - Potential Kernel Module Exfiltration"; flow:to_server; content:"|2e 6b 6f|"; distance:0; within:3; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict root access to the infotainment system via strong authentication and least privilege.
2. Enable kernel module signing by recompiling the kernel with CONFIG_MODULE_SIG_FORCE=y and signing all modules.
3. Implement file integrity monitoring (e.g., AIDE, Tripwire) for kernel module directories (/lib/modules/).
4. Apply mandatory access controls (SELinux, AppArmor) to limit module loading.

Long-Term Fix:

• Nissan must release a firmware update that enables kernel module signature verification.
• Until then, vehicle owners should avoid connecting untrusted USB devices or networks to the infotainment system.

Workaround:

• Disable module loading entirely by setting kernel.modules_disabled=1 in /etc/sysctl.conf (may break legitimate functionality).

Valters IT