Insecure code.py

from flask import Flask, request, render_template, redirect, session
import sqlite3

app = Flask(__name__)
app.secret_key = "secret"

def get_db_connection():
    conn = sqlite3.connect("database.db")
    return conn

@app.route("/")
def home():
    return "Welcome to the secure app!"

@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST":
        username = request.form["username"]
        password = request.form["password"]
        
        conn = get_db_connection()
        cursor = conn.cursor()
        query = f"SELECT * FROM users WHERE username = '{username}' AND password = '{password}'"
        cursor.execute(query)  
        user = cursor.fetchone()
        conn.close()

        if user:
            session["user"] = username
            return redirect("/")
        else:
            return "Invalid credentials"

    return render_template("login.html")

if __name__ == "__main__":
    app.run(debug=True)