Siemens ProductCERT has confirmed a critical improper access control vulnerability in Heliox-branded EV charging hardware that could let attackers reach otherwise protected services simply by using the charging cable. Designated CVE-2025-27769 with a CVSS score of 8.1 (High severity), this vulnerability represents one of the most concerning physical-to-digital attack vectors discovered in EV charging infrastructure to date.

The vulnerability stems from improper access control mechanisms in the charging hardware's communication interfaces. When an EV connects via the charging cable, the system fails to properly authenticate and authorize the connection, potentially allowing malicious actors to bypass network segmentation and access internal services that should remain isolated. This isn't a theoretical concern—attackers could potentially access building management systems, corporate networks, or other critical infrastructure connected to the same network segment as the charging stations.

Technical Details of the Vulnerability

CVE-2025-27769 is classified under CWE-923: Improper Restriction of Communication Channel to Intended Endpoints. The vulnerability affects multiple Heliox charging station models, though Siemens has not publicly disclosed the specific affected versions in their initial advisory. What makes this vulnerability particularly dangerous is its exploitation method—attackers don't need physical access to the charging station's internal components or network ports. The charging cable itself becomes the attack vector.

When an electric vehicle plugs into a vulnerable Heliox charger, the communication protocol between the vehicle and charger establishes a connection that should be restricted to charging-related functions. Due to the improper access controls, this connection can potentially be leveraged to reach other services on the network. The vulnerability doesn't require sophisticated equipment to exploit—an attacker could theoretically use a modified electric vehicle or charging adapter to initiate the attack.

Real-World Impact and Attack Scenarios

The practical implications of CVE-2025-27769 are significant for organizations deploying Heliox charging infrastructure. Charging stations are often connected to corporate networks, building management systems, or utility grids. A successful exploitation could lead to several concerning scenarios:

  • Network Lateral Movement: Attackers could use the charging station as an entry point to move laterally within an organization's network, potentially accessing sensitive systems and data.
  • Critical Infrastructure Compromise: In industrial or utility settings, charging stations might be connected to operational technology networks. Breaching these could disrupt power distribution or industrial processes.
  • Data Exfiltration: Charging stations often collect usage data, payment information, and user credentials. This data could be intercepted or stolen through the vulnerability.
  • Physical Safety Risks: While the advisory doesn't indicate direct physical safety risks, any compromise of charging infrastructure could potentially lead to unsafe charging conditions if attackers manipulate charging parameters.

Siemens' Response and Mitigation Measures

Siemens ProductCERT, which handles security vulnerabilities for Siemens products including Heliox-branded equipment, has released firmware updates to address CVE-2025-27769. Organizations using affected Heliox charging stations should immediately:

  1. Identify Affected Equipment: Determine which Heliox charging stations in your infrastructure might be vulnerable. Siemens recommends contacting their support for specific model and version information.
  2. Apply Firmware Updates: Install the latest firmware updates provided by Siemens/Heliox. These updates implement proper access controls and authentication mechanisms for charging cable communications.
  3. Network Segmentation: Ensure charging stations are placed on isolated network segments with strict firewall rules limiting communication to only necessary services.
  4. Physical Security: While the attack requires physical connection via charging cable, implementing surveillance and access controls around charging stations can deter potential attackers.

The Broader Context of EV Charging Security

CVE-2025-27769 isn't an isolated incident in the EV charging ecosystem. As electric vehicle adoption accelerates globally, charging infrastructure has become an increasingly attractive target for cyberattacks. Several factors contribute to this trend:

  • Rapid Deployment Pressure: The urgent need to expand charging networks has sometimes led to security considerations taking a backseat to deployment speed.
  • Legacy Systems: Some charging equipment runs on older operating systems or uses communication protocols designed before modern security threats were fully understood.
  • Complex Supply Chains: Charging stations often incorporate components from multiple vendors, creating potential vulnerabilities at integration points.
  • Physical Accessibility: Unlike traditional IT infrastructure kept in secure data centers, charging stations are publicly accessible, making them vulnerable to physical tampering.

This vulnerability follows other recent security concerns in EV charging infrastructure, including vulnerabilities in authentication systems, payment processing, and remote management interfaces. The automotive and energy sectors are increasingly recognizing that charging stations represent critical infrastructure requiring enterprise-grade security measures.

Best Practices for EV Charging Security

Organizations deploying or operating EV charging infrastructure should implement comprehensive security measures beyond just patching individual vulnerabilities:

  • Regular Security Assessments: Conduct penetration testing and vulnerability assessments specifically targeting charging infrastructure.
  • Zero Trust Architecture: Implement zero trust principles for charging station networks, verifying every connection attempt regardless of origin.
  • Secure Development Lifecycle: Ensure charging station manufacturers follow secure development practices and provide regular security updates.
  • Incident Response Planning: Develop specific incident response plans for charging infrastructure compromises, including procedures for isolating affected stations and notifying users.
  • Supply Chain Security: Vet charging equipment vendors for their security practices and commitment to timely vulnerability disclosure and patching.

Looking Forward: The Future of Charging Infrastructure Security

The discovery of CVE-2025-27769 highlights a critical juncture for EV charging security. As charging stations evolve from simple power delivery devices to networked energy management systems, their security requirements become increasingly complex. Several developments will shape the future landscape:

  • Standardization Efforts: Industry groups and standards bodies are working to establish security standards specifically for EV charging infrastructure.
  • Regulatory Requirements: Governments worldwide are beginning to implement cybersecurity regulations for critical infrastructure, which increasingly includes EV charging networks.
  • Advanced Authentication: Future charging systems will likely implement more sophisticated authentication mechanisms, potentially including certificate-based authentication for vehicle-to-charger communications.
  • Security-by-Design: Manufacturers are increasingly incorporating security considerations from the initial design phase rather than bolting on security features later.

For organizations currently operating Heliox charging stations, immediate action is required. The combination of high CVSS score, physical accessibility of the attack vector, and potential for network compromise makes CVE-2025-27769 a vulnerability that cannot be ignored. Regular security monitoring, prompt patching, and comprehensive security planning will be essential as EV charging infrastructure continues to expand and evolve.