Integer Overflow Vulnerability in Tesla Model 3 VCSEC Module and Implications for Automotive Security

 

CVE-2025-2082: Integer Overflow Vulnerability in Tesla Model 3 VCSEC Module and Implications for Automotive Security
Abstract
CVE-2025-2082 is a critical security vulnerability identified in the Vehicle Security (VCSEC) module of Tesla Model 3 vehicles, enabling remote code execution (RCE) and CAN bus manipulation via an integer overflow exploit. This article analyzes the technical root causes, attack scenarios, potential impacts, and interim mitigation measures for this vulnerability.

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1. Technical Analysis

Root Cause of the Vulnerability
The VCSEC module mishandles unsigned integer values during the certificate validation process when communicating with the Tire Pressure Monitoring System (TPMS). A maliciously crafted TPMS packet triggers the following steps:

1. Integer Overflow: The data_length field in the TPMS cert_response packet, defined as a 32-bit unsigned integer, is set to 0xFFFFFFFF by an attacker, causing a memory allocation overflow.
2. Heap-Based Buffer Overflow: The overflow results in uncontrolled memory copying (memcpy) in the VCSEC's heap memory, allowing the injection of attacker-defined shellcode.
3. Code Execution and CAN Access: Successful exploitation grants RCE in the VCSEC's privileged context. Attackers can directly manipulate the CAN bus, injecting spoofed messages into critical frames such as 0x1A6 (brake system) or 0x2E4 (motor control unit).

Unique Aspects of the Vulnerability

• Lack of Network-Layer Authentication: No physical access or user credentials are required; attackers need only to be on the same network segment (Wi-Fi/Bluetooth).
• Direct CAN Bus Access: Unlike other automotive vulnerabilities, this flaw grants full control over in-vehicle communication.

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2. Attack Scenarios and Impacts

Potential Scenarios

• Brake System Disabling: CAN messages like Brake_Actuator_Status set to 0x00 could abruptly disable brakes.
• Motor Power Manipulation: Altering Motor_Control_Unit frames may force the vehicle to halt or accelerate uncontrollably.
• Door Lock Exploitation: Unauthorized access to the Body_Control_Module could remotely unlock doors.

Industry-Wide Risks

• Convergence of Safety and Comfort Systems: Modern vehicles integrate safety-critical systems (e.g., brakes) with low-priority systems (e.g., TPMS) on shared networks. This vulnerability demonstrates how a non-critical system (TPMS) can expose high-risk attack surfaces.

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3. Mitigations and Recommendations

Immediate Actions

• Network Segmentation: Physically isolate TPMS communications from the VCSEC and CAN bus using VLANs or dedicated buses.
• Input Validation: Enforce bounds checks for data_length (e.g., 0 < data_length < 1024) during cert_response processing.

Long-Term Solutions

• TPMS Traffic Encryption: Implement AES-256 or similar protocols to encrypt TPMS communications.
• CAN Bus Whitelisting: Filter unauthorized frames using ID-based allowlists.

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4. Conclusion and Call to Action

CVE-2025-2082 underscores the dangers of "security by obscurity" in automotive cybersecurity. Manufacturers must adopt rigorous code audits for embedded systems and urgently comply with ISO/SAE 21434 standards. This vulnerability serves as a stark reminder that flaws in cyber-physical systems can directly endanger human lives. Proactive collaboration between researchers, automakers, and regulators is critical to safeguarding the future of connected vehicles.