Predictable Session Identifier in Charging Station Backend

Compliance Impact

The provided information does not specify any direct impact of the vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.

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Detection Guidance

Detection of this vulnerability involves monitoring for multiple WebSocket connections using the same session identifier, which indicates predictable session IDs and potential unauthorized access attempts.

Network administrators should look for unusual patterns such as multiple simultaneous connections from different endpoints sharing the same charging station identifier.

Commands or tools to assist in detection may include using network traffic analyzers like Wireshark or tcpdump to capture WebSocket traffic and filter for repeated session identifiers.

• Use tcpdump to capture WebSocket traffic on the relevant port (e.g., port 80 or 443): tcpdump -i <interface> port 80 or port 443 -w capture.pcap
• Analyze the capture with Wireshark to filter WebSocket frames and inspect session identifiers for duplicates.
• Use custom scripts or log analysis tools to parse backend logs for multiple connections sharing the same session ID.

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Mitigation Strategies

Immediate mitigation steps include implementing server-side protections to enforce single active connections per charging station identifier and adding rate-limiting controls on authentication requests.

Minimize network exposure of the charging station management system by isolating control systems and using secure remote access methods such as VPNs.

Migrating legacy chargers to stronger security profiles (OCPP Security Profiles 2 or 3) is recommended to enhance authentication mechanisms.

• Enforce allow-listing of authorized devices or endpoints to restrict access.
• Implement rate limiting on authentication attempts to prevent brute-force or denial-of-service attacks.
• Isolate the charging station management system network segment from general enterprise networks.

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Executive Summary

This vulnerability exists in the WebSocket backend that uses charging station identifiers to uniquely associate sessions. However, it allows multiple endpoints to connect using the same session identifier, resulting in predictable session identifiers.

Because of this, unauthorized users may be able to authenticate as other users or a malicious actor could cause a denial-of-service condition by overwhelming the backend with valid session requests.

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Impact Analysis

This vulnerability can impact you by allowing unauthorized users to impersonate other users, potentially gaining access to restricted functions or data.

Additionally, it can enable attackers to launch denial-of-service attacks by flooding the backend with valid session requests, which could disrupt service availability.

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