CVE-2025-32057: Nissan Leaf Infotainment ECU SSL Vulnerability

CVE-2025-32057 Overview

CVE-2025-32057 is an improper certificate validation flaw [CWE-295] affecting the Bosch-manufactured infotainment Electronic Control Unit (ECU) installed in the Nissan Leaf ZE1 (2020). The ECU relies on a Redbend service for over-the-air (OTA) provisioning and firmware updates. Communication with the Redbend back-end server uses HTTPS, but the underlying SSL engine is left in its default configuration and does not verify the server root certificate. An attacker positioned on the network path can impersonate the Redbend backend using a self-signed certificate. The issue was first identified on Nissan Leaf ZE1 vehicles manufactured in 2020.

Critical Impact
A network-adjacent attacker can impersonate the Redbend OTA server and intercept or manipulate provisioning traffic to the vehicle's infotainment ECU.

Affected Products

Bosch Infotainment ECU installed in Nissan Leaf ZE1 (2020)
Redbend OTA provisioning and update service running on the ECU
SSL/TLS client stack shipped with the default ECU configuration

Discovery Timeline

2026-01-22 - CVE-2025-32057 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-32057

Vulnerability Analysis

The infotainment ECU establishes HTTPS sessions with the Redbend back-end for OTA provisioning and firmware updates. The SSL engine on the client side is initialized with default parameters, and the code path responsible for validating the peer certificate chain does not enforce verification against a trusted root store. Any certificate presented by the peer, including a self-signed certificate, is accepted as valid. This breaks the trust guarantees HTTPS is meant to provide and reduces the transport to encrypted-but-unauthenticated communication. Successful exploitation requires user interaction and network positioning, and it affects confidentiality of the OTA channel while integrity and availability of the underlying vehicle systems are not directly impacted by this specific flaw.

Root Cause

The root cause is missing server certificate validation in the Redbend client's TLS configuration, classified as Improper Certificate Validation [CWE-295]. The default SSL engine configuration was retained instead of pinning the Redbend root certificate or enforcing strict chain validation, so certificate authenticity checks are effectively bypassed.

Attack Vector

An attacker who can intercept the ECU's outbound traffic — for example through a rogue cellular base station, a hostile Wi-Fi hotspot, or upstream network tampering — presents a self-signed certificate impersonating the Redbend backend. The ECU accepts the certificate and completes the TLS handshake with the attacker-controlled server. From that position the attacker can read provisioning data, deliver crafted responses, or serve as a pivot for chained attacks against the update mechanism. Technical exploitation details were presented at Black Hat Asia 2025 in Remote Exploitation of Nissan Leaf and in the PCA Cybersecurity Advisory on Nissan Vulnerabilities.

No verified proof-of-concept code has been published. The vulnerability is described in the referenced advisories and conference material rather than as reusable exploit code.

Detection Methods for CVE-2025-32057

Indicators of Compromise

TLS sessions from the infotainment ECU terminating on IP addresses or hostnames that do not belong to the legitimate Redbend infrastructure.
Server certificates presented to the ECU that are self-signed or issued by an unexpected certificate authority.
Unexpected OTA provisioning attempts, firmware push notifications, or configuration changes occurring outside of scheduled Nissan update windows.

Detection Strategies

Inspect cellular and Wi-Fi backhaul traffic from vehicle fleets for TLS handshakes to Redbend endpoints and validate that presented certificates chain to the expected root.
Compare observed Redbend server certificate fingerprints against a known-good baseline captured from a trusted network path.
Monitor for anomalies in OTA download volumes, unexpected retries, or firmware version drift across similar vehicles.

Monitoring Recommendations

Log DNS resolutions and destination IPs for Redbend hostnames from fleet telematics gateways where available.
Alert on repeated TLS negotiations from vehicle ECUs to non-approved backend infrastructure.
Track OTA update events and correlate them with official Nissan and Bosch release schedules to identify out-of-band activity.

How to Mitigate CVE-2025-32057

Immediate Actions Required

Contact Nissan and authorized dealerships to confirm the current infotainment firmware level on affected Leaf ZE1 (2020) vehicles and apply any available service campaign updates.
Avoid connecting affected vehicles to untrusted Wi-Fi networks or tethered hotspots that could be used to intercept OTA traffic.
For fleet operators, restrict or monitor cellular backhaul used by infotainment ECUs and route it through inspected network paths where feasible.

Patch Information

No vendor patch identifier is listed in the NVD entry for CVE-2025-32057 at the time of publication. Owners and fleet operators should track the PCA Cybersecurity Advisory on Nissan Vulnerabilities and Nissan service bulletins for the Leaf ZE1 platform. Remediation requires Bosch and Redbend to ship an ECU firmware update that enforces server certificate validation, ideally with certificate pinning against the Redbend backend.

Workarounds

Where operationally acceptable, disable or defer OTA provisioning on affected ECUs until updated firmware is available.
Ensure vehicles receive updates only through trusted service center networks rather than public or unmanaged wireless environments.
For research and test fleets, apply network-layer controls that restrict the ECU to a curated allowlist of Redbend backend IP ranges.

bash

# Configuration example not available - CVE-2025-32057 requires vendor firmware
# remediation from Bosch/Redbend to enforce server certificate validation.
# Refer to Nissan service bulletins for the Leaf ZE1 (2020) platform.