CVE-2025-32062

Executive Summary

CVE-2025-32062 is a critical stack-based buffer overflow vulnerability in the Bluetooth stack developed by Alps Alpine, integrated into the Infotainment ECU manufactured by Bosch. The flaw allows an unauthenticated attacker within Bluetooth range to send a specially crafted packet over an established upper-layer L2CAP channel, leading to remote code execution (RCE) with root privileges on the Infotainment ECU. The vulnerability was first identified on the Nissan Leaf ZE1 (2020 model), but the underlying component may be present in other vehicles using the same Bosch ECU.

The CVSS score is 8.8 (High), with a vector emphasizing low attack complexity and no user interaction. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild at the time of analysis, but the impact is severe due to the potential for full vehicle compromise.

Note: This vulnerability is not related to any WordPress plugin or component; it is a hardware/embedded system issue.

Supply Chain & Package Security

This vulnerability is not in an NPM, PyPI, Go, or Ruby package. It resides in a proprietary Bluetooth stack embedded in automotive hardware. Supply chain risk is high due to the closed-source nature of the component and the lack of a patch.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Base Score: 8.8 (High)
• Attack Vector (AV): Adjacent Network (Bluetooth range, typically ~10-100m)
• Attack Complexity (AC): Low (no special conditions required)
• Privileges Required (PR): None
• User Interaction (UI): None
• Scope (S): Unchanged
• Confidentiality (C): High
• Integrity (I): High
• Availability (A): High

Threat Level: Critical for automotive safety. An attacker can gain root access to the Infotainment ECU, potentially controlling vehicle functions, exfiltrating data, or pivoting to other ECUs.

Deep Dive & Mechanics

The vulnerability exists in the Bluetooth stack's handling of L2CAP (Logical Link Control and Adaptation Protocol) packets. When a specific upper-layer L2CAP channel is established, the stack fails to validate the size of incoming data. An attacker can send a packet with a payload larger than the allocated stack buffer, causing a stack-based buffer overflow.

Technical Details:

• Component: Alps Alpine Bluetooth stack (proprietary, closed-source)
• Protocol: Bluetooth L2CAP (Logical Link Control and Adaptation Protocol)
• Trigger: A crafted packet on an established upper-layer L2CAP channel (e.g., RFCOMM, SDP, or custom profile)
• Root Cause: Lack of boundary validation on user-supplied data before copying to a stack buffer
• Impact: Overwriting the return address and other stack data, leading to arbitrary code execution with root privileges

Attack Scenario:

1. Attacker discovers a vehicle with the vulnerable Infotainment ECU (e.g., Nissan Leaf ZE1).
2. Attacker pairs or connects via Bluetooth (no authentication required for L2CAP connection).
3. Attacker sends a malicious L2CAP packet with oversized payload.
4. Stack overflow occurs, overwriting the return address.
5. Attacker gains a root shell on the Infotainment ECU.

Vulnerable vs. Patched Code

Since the component is closed-source, no code diff is available. However, the vulnerability is a classic stack buffer overflow. The patched version would include boundary checks before copying data to the stack buffer.

Vulnerable (pseudocode):

void process_l2cap_packet(uint8_t *data, uint16_t len) {
    char buffer[256];
    // No length check
    memcpy(buffer, data, len); // Overflow if len > 256
}

Patched (pseudocode):

void process_l2cap_packet(uint8_t *data, uint16_t len) {
    char buffer[256];
    if (len > sizeof(buffer)) {
        // Reject packet
        return;
    }
    memcpy(buffer, data, len);
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Bluetooth adapter (e.g., CSR 4.0 dongle)
• Python with pybluez or scapy for Bluetooth packet crafting
• Target vehicle with vulnerable Infotainment ECU (e.g., Nissan Leaf ZE1)

Exploit Steps:

1. Scan for Bluetooth devices:

   hcitool scan
   

2. Connect to the target ECU's Bluetooth service (e.g., RFCOMM channel):

   import bluetooth
   sock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
   sock.connect(("XX:XX:XX:XX:XX:XX", 1))
   

3. Craft a malicious L2CAP packet with a payload that overflows the stack:

   import struct
   # Craft payload: NOP sled + shellcode + return address
   payload = b"\x90" * 200  # NOP sled
   payload += shellcode     # Reverse shell or root shell
   payload += struct.pack("<I", 0xdeadbeef)  # Overwrite return address
   sock.send(payload)
   

4. Receive shell:

   nc -lvnp 4444
   

Note: No public exploit code is available; this is a conceptual example.

Blue Team (Defense)

Detection:

• Monitor Bluetooth L2CAP traffic for oversized packets (e.g., > 256 bytes on control channels).
• Use host-based IDS on the Infotainment ECU (if possible) to detect stack corruption.

Mitigation:

• Disable Bluetooth if not needed.
• Apply network segmentation: isolate Infotainment ECU from critical vehicle systems.
• Monitor for unexpected Bluetooth connections or pairing attempts.

Indicators of Compromise (IOCs)

• Network:
  • Bluetooth L2CAP packets with payload length > 256 bytes on established channels
  • Unexpected RFCOMM or SDP connections from unknown devices
• Host (Infotainment ECU):
  • Unusual processes running as root
  • Modified system binaries or scripts
  • Outbound connections to unknown IPs (e.g., reverse shell)
• Logs:
  • Bluetooth stack crashes or reboots
  • Kernel panics related to Bluetooth driver

Detection Engineering

YARA Rule

rule CVE_2025_32062_Bluetooth_Overflow {
    meta:
        description = "Detects potential stack overflow in Alps Alpine Bluetooth stack"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-32062"
    strings:
        $l2cap_header = { 02 ?? ?? ?? }  // L2CAP frame with channel ID
        $large_payload = { 01 00 01 00 }  // Example pattern
    condition:
        $l2cap_header and #large_payload > 10
}

Sigma Rule

title: CVE-2025-32062 Bluetooth Stack Overflow Detection
id: 8f9a2b3c-4d5e-6f7a-8b9c-0d1e2f3a4b5c
status: experimental
description: Detects oversized Bluetooth L2CAP packets indicative of exploitation
author: Valters IT
logsource:
    product: linux
    service: bluetooth
detection:
    selection:
        EventID: 1001  # Example: Bluetooth stack error
        DataLength: ">256"
    condition: selection
falsepositives:
    - Legitimate large Bluetooth packets (rare)
level: high

Suricata Rule

alert bluetooth any any -> any any (msg:"CVE-2025-32062 Bluetooth L2CAP Buffer Overflow Attempt"; content:"|02 00|"; offset:0; depth:2; content:"|01 00|"; within:10; byte_test:2,>,256,4; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable Bluetooth on the Infotainment ECU if not required.
2. Apply network segmentation to isolate the Infotainment ECU from critical vehicle systems (e.g., CAN bus, braking, steering).
3. Monitor Bluetooth logs for unusual activity.

Long-term:

• Vendor Patch: Await official firmware update from Bosch or Nissan. Contact Bosch for patch status.
• Workaround: If Bluetooth is necessary, restrict pairing to authorized devices only and disable unnecessary Bluetooth profiles.
• Compensating Controls: Implement host-based intrusion detection on the ECU (if supported) to detect stack corruption.

Valters IT Signature: This report was generated by Valters IT, an elite DevSecOps and Cyber Threat Intelligence team. For questions, contact: security@valters-it.com