CVE-2023-26246 in Gen5W_L
Summary
by MITRE • 04/27/2023
An issue was discovered in the Hyundai Gen5W_L in-vehicle infotainment system AE_E_PE_EUR.S5W_L001.001.211214. The AppUpgrade binary file, which is used during the firmware installation process, can be modified by an attacker to bypass the digital signature check. This indirectly allows an attacker to install custom firmware in the IVI system.
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Analysis
by VulDB Data Team • 04/06/2026
The vulnerability identified as CVE-2023-26246 resides within the Hyundai Gen5W_L in-vehicle infotainment system, specifically affecting the AE_E_PE_EUR.S5W_L001.001.211214 software version. This represents a critical security flaw in the vehicle's firmware update mechanism that undermines the integrity of the system's software installation process. The issue manifests through the AppUpgrade binary file, which serves as a crucial component during firmware installation but contains a significant weakness in its digital signature validation process. This vulnerability directly impacts the automotive cybersecurity posture of affected Hyundai vehicles, potentially allowing unauthorized modifications to critical in-vehicle systems.
The technical flaw stems from insufficient digital signature verification within the firmware update binary. When the AppUpgrade component executes during the firmware installation process, it fails to properly validate the authenticity of the firmware image being installed. This weakness creates a pathway for attackers to manipulate the upgrade process by replacing the legitimate firmware with malicious custom firmware. The vulnerability operates at the system level where software integrity checks are bypassed, allowing attackers to install unauthorized code without proper authentication. This represents a direct violation of the principle of least privilege and software integrity protection mechanisms that should prevent unauthorized modifications to critical vehicle systems.
The operational impact of this vulnerability extends beyond simple unauthorized software installation, creating potential security risks for vehicle occupants and the broader connected vehicle ecosystem. An attacker who successfully exploits this vulnerability could install malicious firmware that compromises vehicle functionality, potentially affecting critical systems such as braking, steering, or entertainment features. The implications align with attack patterns described in the MITRE ATT&CK framework under the software supply chain attack category, specifically targeting the firmware and software update processes. This vulnerability could enable persistent threats that remain undetected even after vehicle restarts, as the malicious firmware would be installed at the system level.
The security implications of CVE-2023-26246 are particularly concerning given the increasing reliance on connected vehicle systems and the potential for remote exploitation. This vulnerability could be exploited through various attack vectors including physical access to the vehicle's diagnostic interfaces or potentially through network-based attacks targeting the infotainment system. The flaw represents a weakness in the automotive cybersecurity maturity model, specifically affecting the software integrity and update security controls. Organizations implementing automotive security frameworks such as ISO/SAE 21434 should consider this vulnerability as a critical finding that requires immediate remediation and enhanced monitoring protocols. The vulnerability's classification aligns with CWE-311, which addresses the absence of encryption or other security mechanisms to protect sensitive data during transmission or storage.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Hyundai, implementing network segmentation for vehicle systems, and establishing robust monitoring for unauthorized firmware modifications. Vehicle manufacturers should enhance their software integrity verification mechanisms and implement multi-layered security controls that prevent bypassing of digital signature checks. The vulnerability highlights the need for comprehensive automotive cybersecurity frameworks that address the entire software development lifecycle, including secure update mechanisms and proper validation of software integrity. Organizations should also consider implementing intrusion detection systems specifically designed for vehicle networks and establishing secure development practices that prevent similar flaws in future vehicle software releases.