Arp Spoofing in Sqlite

ARP spoofing is a layer-2 network attack where an attacker sends falsified ARP messages to link their MAC address with the IP address of a legitimate host (like a gateway or server). This enables man-in-the-middle (MITM) interception of traffic. While SQLite itself is a file-based database engine and not directly vulnerable to ARP spoofing, the attack becomes critically relevant when SQLite is used as the backend for a network-accessible API—especially one exposed over unencrypted HTTP.

Consider a common architecture: a lightweight REST API built with a framework like Flask (Python) or Express (Node.js), using SQLite for data persistence. If this API listens on a local network interface without TLS, an attacker on the same LAN can ARP spoof the API server's IP. Once positioned as a MITM, they can:

• Intercept and read sensitive data: Capture API requests/responses containing PII, credentials, or session tokens stored in or retrieved from SQLite.
• Inject malicious queries: Modify HTTP parameters or JSON bodies to perform SQL injection (e.g., altering a user_id parameter to 1 OR 1=1), exploiting the SQLite database's trust in the incoming query.
• Session hijacking: Steal authentication cookies or JWTs transmitted in cleartext, then access the API with elevated privileges (BOLA/IDOR vulnerabilities might then allow unauthorized data extraction from SQLite).
• Data corruption: Send forged POST/PUT requests to overwrite SQLite records (e.g., changing a user's role from user to admin).

A concrete code path where this manifests is in a typical SQLite query execution without parameterization. For example, in Python with the sqlite3 module:

import sqlite3, flask
app = flask.Flask(__name__)

@app.route('/user')
def get_user():
    user_id = flask.request.args.get('id')  # Unvalidated input
    conn = sqlite3.connect('app.db')
    cursor = conn.cursor()
    cursor.execute(f"SELECT * FROM users WHERE id = {user_id}")  # Vulnerable to SQLi
    return flask.jsonify(cursor.fetchall())

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)  # HTTP, no TLS

If an attacker ARP spoofs the server and intercepts a request like GET /user?id=1, they could modify it to GET /user?id=1 UNION SELECT credit_card FROM payments--. The API, running over HTTP, forwards this malicious query to SQLite, which executes it due to the string concatenation, exposing sensitive data from another table.

This attack chain (ARP spoofing → MITM → SQL injection → data exfiltration) is particularly dangerous because SQLite's file-based nature means a single compromised API endpoint can expose the entire database file if the attacker can also exploit path traversal (e.g., ../../app.db) or if the API runs with excessive filesystem permissions.

Detecting ARP spoofing risks in SQLite-backed APIs requires a two-pronged approach: network-layer checks and application-layer analysis. Since ARP spoofing is a network attack, its presence is often indicated by the absence of cryptographic protections at the API layer. middleBrick's scanning methodology directly addresses this by evaluating the API's exposure surface.

1. Scan for Missing Transport Security: Use middleBrick to submit the API endpoint URL. The scanner checks for HTTPS enforcement, HSTS headers, and TLS configuration. An 'F' grade in the Encryption category or a finding like "API accessible over HTTP" signals that traffic is unencrypted, making ARP spoofing viable for eavesdropping or tampering. For example, scanning http://api.example.com:5000/user will flag the lack of TLS.

2. Identify Input Validation Weaknesses: middleBrick's Input Validation checks test for SQL injection patterns specific to SQLite's syntax (e.g., UNION SELECT, sqlite_master table access). A finding such as "Potential SQL injection via id parameter" combined with missing encryption creates a high-risk path for ARP-spoofing-enabled attacks. Unlike databases like MySQL, SQLite uses a different set of system tables (sqlite_master) and comment syntax (-- or /* */), which the scanner's probes account for.

3. Verify Authentication and Authorization: If the API lacks proper authentication (middleBrick's Authentication check) or has BOLA/IDOR flaws (BOLA/IDOR category), an ARP-spoofing attacker can more easily hijack sessions or directly access unauthorized SQLite data. middleBrick reports these as separate findings, but their combination with weak encryption elevates overall risk.

4. Manual Network Verification: While middleBrick focuses on the API layer, defenders should complement it with network tools. Use arp-scan or ettercap on the local network to detect ARP spoofing. For a SQLite API, monitor for duplicate IP-MAC mappings:

sudo arp-scan --local

Example middleBrick CLI usage for detection:

middlebrick scan http://api.example.com:5000 --format json

Remediation focuses on securing both the API transport layer and the SQLite interaction layer to break the attack chain. The goal is to ensure that even if ARP spoofing occurs, encrypted traffic prevents reading/modifying queries, and robust SQLite usage prevents injection.

1. Enforce HTTPS with HSTS: Configure the API server to use TLS 1.2+ and redirect all HTTP to HTTPS. Add HTTP Strict Transport Security (HSTS) headers to prevent downgrade attacks. For a Flask app:

from flask_talisman import Talisman
app = Flask(__name__)
Talisman(app, force_https=True, session_cookie_secure=True)

2. Use Parameterized Queries for SQLite: Never concatenate user input into SQLite queries. Use parameterized statements to separate code from data. In Python's sqlite3:

cursor.execute("SELECT * FROM users WHERE id = ?", (user_id,))

const stmt = db.prepare('SELECT * FROM users WHERE id = ?');
const user = stmt.get(user_id);

3. Enable SQLite Encryption (SEE or SQLCipher): If the SQLite database file (app.db) could be stolen (e.g., via a separate file disclosure vulnerability), encrypt it at rest. Use SQLite Encryption Extension (SEE) or the open-source SQLCipher. For SQLCipher in Python:

import sqlcipher3
conn = sqlcipher3.connect('encrypted.db')
conn.execute("PRAGMA key='your-secret-key'")
# Then create tables normally

4. Implement Certificate Pinning for Mobile/Desktop Clients: If the API is consumed by a mobile app that uses a local SQLite cache, pin the server's TLS certificate to prevent MITM even with a compromised CA. In Android (Kotlin):

val certificatePinner = CertificatePinner.Builder()
    .add("api.example.com", "sha256/YourPublicKeyHash")
    .build()
val client = OkHttpClient.Builder().certificatePinner(certificatePinner).build()

5. Network Segmentation and ARP Monitoring: Deploy the API server on a segregated VLAN with static ARP entries on critical gateways. Use tools like arpwatch to alert on MAC address changes. While not a code fix, this reduces the attack surface at the infrastructure level.

6. Validate and Sanitize All Inputs: Beyond SQLite parameterization, validate input types and lengths at the API layer. For example, ensure user_id is an integer:

try:
    user_id = int(flask.request.args.get('id'))
except (TypeError, ValueError):
    return 'Invalid ID', 400

Remediation should be verified by re-scanning with middleBrick after fixes. The Encryption and Input Validation category scores should improve, and findings related to SQLite injection should disappear.