CVE-2025-32059: Bluetooth Stack RCE Vulnerability

CVE-2025-32059 Overview

CVE-2025-32059 is a stack-based buffer overflow vulnerability affecting the Bluetooth stack developed by Alps Alpine within the Infotainment ECU manufactured by Bosch. The vulnerability stems from improper boundary validation of user-supplied data when processing packets on an established upper layer L2CAP (Logical Link Control and Adaptation Protocol) channel. Successful exploitation enables remote code execution with root privileges on the Infotainment ECU.

This vulnerability was first identified on the Nissan Leaf ZE1 manufactured in 2020, representing a significant risk for connected vehicle security. The adjacent network attack vector means an attacker must be within Bluetooth range of the target vehicle to exploit this flaw.

Critical Impact

Remote code execution with root privileges on vehicle Infotainment ECU via Bluetooth, potentially enabling attackers to compromise vehicle systems from adjacent network proximity.

Affected Products

• Nissan Leaf ZE1 (2020 model year)
• Bosch Infotainment ECU with Alps Alpine Bluetooth stack
• Vehicles utilizing affected Alps Alpine Bluetooth stack implementations

Discovery Timeline

• 2026-02-15 - CVE-2025-32059 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2025-32059

Vulnerability Analysis

This vulnerability is classified under CWE-121 (Stack-based Buffer Overflow), a memory corruption flaw that occurs when data written to a buffer exceeds its allocated space on the stack. In the context of CVE-2025-32059, the Alps Alpine Bluetooth stack fails to properly validate the length of incoming data packets received over an L2CAP channel.

The L2CAP protocol operates at the Bluetooth data link layer and provides connection-oriented and connectionless data services to upper layer protocols. When a malicious packet is sent to a vulnerable device over an established L2CAP connection, the Bluetooth stack copies the packet data to a fixed-size stack buffer without adequate bounds checking. This allows an attacker to overwrite adjacent stack memory, including the return address, enabling arbitrary code execution.

The exploitation requires the attacker to first establish a Bluetooth connection with the target vehicle's Infotainment system, then send a specially crafted packet designed to trigger the buffer overflow. Because the Bluetooth stack runs with elevated privileges, successful exploitation results in root-level access to the Infotainment ECU.

Root Cause

The root cause is inadequate input validation within the Alps Alpine Bluetooth stack's L2CAP packet handling routines. Specifically, the code responsible for processing incoming L2CAP data does not verify that the packet payload length falls within expected boundaries before copying data into a stack-allocated buffer. This absence of boundary checks allows attacker-controlled data to overflow the buffer and corrupt adjacent stack memory.

Attack Vector

The attack requires adjacent network access via Bluetooth, meaning the attacker must be within Bluetooth radio range of the target vehicle (typically up to 100 meters for Class 1 Bluetooth devices). The attack flow involves:

1. Scanning for Bluetooth-enabled vehicles with vulnerable Infotainment systems
2. Establishing a Bluetooth connection and negotiating an L2CAP channel
3. Transmitting a maliciously crafted packet with oversized payload data
4. Overflowing the stack buffer to overwrite the return address
5. Redirecting execution to attacker-controlled shellcode for root-level code execution

The vulnerability requires no user interaction and no prior authentication, making it particularly dangerous for vehicles in public locations where an attacker could approach undetected.

Detection Methods for CVE-2025-32059

Indicators of Compromise

• Unusual Bluetooth connection attempts or pairing requests to vehicle Infotainment systems
• Anomalous L2CAP packet sizes exceeding expected protocol boundaries
• Unexpected processes or services running on the Infotainment ECU
• Modifications to system files or configurations on the ECU
• Network traffic anomalies originating from the Infotainment system

Detection Strategies

• Monitor Bluetooth controller logs for malformed or oversized L2CAP packets
• Implement intrusion detection systems capable of analyzing Bluetooth traffic patterns
• Deploy anomaly detection for unexpected root-level process activity on ECU systems
• Review Infotainment system logs for crash events or unexpected restarts indicative of exploitation attempts

Monitoring Recommendations

• Enable comprehensive logging on vehicle Infotainment systems where supported
• Implement network segmentation to isolate Infotainment ECU from critical vehicle systems
• Conduct regular security assessments of Bluetooth-enabled vehicle components
• Monitor for security advisories from Bosch, Alps Alpine, and vehicle manufacturers

How to Mitigate CVE-2025-32059

Immediate Actions Required

• Contact your vehicle manufacturer or dealer for information on available security updates
• Disable Bluetooth functionality on the Infotainment system if not required for essential operations
• Avoid parking in areas where attackers could maintain prolonged proximity to the vehicle
• Monitor manufacturer communications for firmware updates addressing this vulnerability

Patch Information

At the time of publication, specific patch details should be obtained directly from the vehicle manufacturer (Nissan) or component suppliers (Bosch, Alps Alpine). Vehicle owners should consult the PCA Cybersecurity Advisory on Nissan Vulnerabilities for updated remediation guidance. The BlackHat Presentation on Nissan Exploitation provides additional technical context for security professionals.

Workarounds

• Disable Bluetooth on the Infotainment system through vehicle settings if the feature is not needed
• Limit Bluetooth discoverability to prevent unauthorized connection attempts
• Park vehicles in secure, access-controlled environments to reduce attacker proximity opportunities
• Consider aftermarket security solutions that provide additional monitoring for connected vehicle systems

# Bluetooth service management (if accessible via diagnostic interface)
# Consult vehicle documentation before modifying system settings
# Example: Disabling Bluetooth service at system level
systemctl disable bluetooth.service
systemctl stop bluetooth.service