robsware

The vulnerability is Deserialization of Untrusted Data

python
from flask import Flask, request
import pickle

app = Flask(__name__)

class User:
    def __init__(self, name, age, email):
        self.name = name
        self.age = age
        self.email = email

@app.route('/', methods=['POST'])
def index():
    user_data = request.form.get('user_data')
    user = pickle.loads(user_data)
    return f'Welcome, {user.name}, ({user.email})'

if __name__ == '__main__':
    app.run()

python
from flask import Flask, request
import json

app = Flask(__name__)

class User:
    def __init__(self, name, age, email):
        self.name = name
        self.age = age
        self.email = email

@app.route('/', methods=['POST'])
def index():
    user_data = json.loads(request.form.get('user_data'))
    user = User(user_data['name'], user_data['age'], user_data['email'])
    return f'Welcome, {user.name}, ({user.email})'

if __name__ == '__main__':
    app.run()

This code snippet is vulnerable to Deserialization of Untrusted Data because it uses `pickle` module to serialize and deserialize the `Employee` object. This module does not check for malicious code, which means an attacker can send a malicious payload to execute arbitrary code on the victim's machine. To fix this vulnerability, use a safe serialization format like `json` or `yaml`. Fixed code:

python
import json

class Employee:
    def __init__(self, name, age):
        self.name = name
        self.age = age

employee = Employee('John', 25)

serialized_employee = json.dumps({'name': employee.name, 'age': employee.age})

deserialized_employee = json.loads(serialized_employee)

print(deserialized_employee)