Source: security-advisories@github.com
Signal K Server is a server application that runs on a central hub in a boat. An unauthenticated information disclosure vulnerability in versions prior to 2.19.0 allows any user to retrieve sensitive system information, including the full SignalK data schema, connected serial devices, and installed analyzer tools. This exposure facilitates reconnaissance for further attacks. Version 2.19.0 patches the issue.
Unauthenticated information disclosure vulnerability in Signal K Server allows attackers to retrieve sensitive system data, including the data schema, connected devices, and installed tools. This reconnaissance vulnerability enables attackers to gain critical insights into the target system, potentially leading to further exploitation and complete system compromise. Immediate patching to version 2.19.0 or later is crucial.
Step 1: Reconnaissance: The attacker identifies a vulnerable Signal K Server instance, likely through port scanning or other reconnaissance techniques. Step 2: Request Construction: The attacker crafts a specific HTTP request to an endpoint known to expose sensitive information (e.g., the data schema endpoint, device listing endpoint). The request does not require any authentication credentials. Step 3: Information Retrieval: The attacker sends the crafted request to the vulnerable server. Step 4: Response Analysis: The server, lacking proper authentication, responds with the requested sensitive information, including the Signal K data schema, connected serial devices, and installed analyzer tools. Step 5: Attack Planning: The attacker analyzes the retrieved information to identify potential attack vectors, such as vulnerable devices, software versions, or misconfigurations.
The vulnerability stems from a lack of proper authentication and authorization checks within the Signal K Server. Specifically, the server fails to restrict access to sensitive information endpoints. The root cause is likely a missing or inadequate access control mechanism, allowing any unauthenticated user to query and retrieve internal system data. This could be due to a default configuration that exposes internal APIs or a coding error that bypasses security checks. The absence of proper input validation could also contribute to the vulnerability, potentially allowing for more sophisticated attacks beyond simple information disclosure.
While no specific APT groups are directly linked to this vulnerability at this time, the nature of the target (marine electronics) suggests potential interest from groups targeting maritime infrastructure or those seeking to disrupt navigation systems. This vulnerability could be leveraged by any attacker with basic network skills. CISA KEV status: Not Listed.
Network traffic analysis: Monitor for unusual HTTP requests to Signal K Server endpoints, especially those known to expose sensitive information (e.g., /signalk/v1/api/schema, /signalk/v1/api/devices).
Log analysis: Examine Signal K Server logs for unauthorized access attempts or suspicious activity. Look for requests without authentication headers.
File integrity monitoring: Monitor critical Signal K Server configuration files for unauthorized modifications.
Honeypots: Deploy honeypots that mimic Signal K Server to attract and detect malicious activity.
Upgrade to Signal K Server version 2.19.0 or later immediately.
Implement strong authentication and authorization mechanisms for all Signal K Server API endpoints.
Review and harden the Signal K Server configuration, ensuring that sensitive information is not exposed by default.
Regularly update all software and firmware on the boat's network.
Implement network segmentation to isolate the Signal K Server from other critical systems.
Monitor network traffic for suspicious activity and unauthorized access attempts.