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Privilege escalation

Need​

Enhancement of role-based access control to prevent unauthorized privilege escalation

Context​

  • Usage of Python 3 for writing and executing Python code
  • Usage of Django for building web applications in Python

Description​

Non compliant code​

from django.contrib.auth.models import User

def elevate_privileges(request):
    user = request.user
    user.is_superuser = True
    user.save()

In the above code, the function elevate_privileges is designed to elevate the privileges of the current user to superuser status.

The function first pulls the current user object from the request. It then sets the is_superuser attribute of the user object to True and saves the user object back to the database.

This code is vulnerable to privilege escalation because it allows any authenticated user to become a superuser. This means that even a standard user, who should have limited privileges, can gain administrative access and perform any action on the system, including actions that should be restricted to administrators only.

The vulnerability exists because there is no check to ensure that the user has the necessary permissions to elevate their privileges. Any authenticated user can call this function and become a superuser. This is a serious security flaw that could lead to unauthorized access and control of the system.

Steps​

  • Check the user's current role before elevating privileges. Only allow privilege escalation for users with specific roles, such as 'admin' or 'superuser'.
  • Implement a multi-factor authentication system for privilege escalation. This could involve sending a verification code to the user's registered email or phone number.
  • Log all attempts at privilege escalation. This will help you identify any suspicious activity.
  • Limit the number of times a user can attempt to escalate their privileges. After a certain number of failed attempts, lock the account and notify the system administrator.
  • Regularly review and update your role configuration settings to ensure they are secure.

Compliant code​

from django.contrib.auth.models import User
from django.contrib.auth.decorators import user_passes_test

def check_is_admin(user):
    return user.is_superuser

@user_passes_test(check_is_admin, login_url='login_page')
def elevate_privileges(request):
    user = request.user
    user.is_superuser = True
    user.save()

The updated code includes a function check_is_admin(user) that checks if the user is a superuser. This function is used as a decorator @user_passes_test(check_is_admin, login_url='login_page') for the elevate_privileges(request) function.

The user_passes_test decorator is a built-in Django decorator that checks whether a user passes the given test, which is defined by check_is_admin(user) in this case. If the user is not a superuser, they are redirected to the login page.

This way, only users who are already superusers can elevate their privileges, which prevents privilege escalation vulnerability.

Please note that this is a basic solution and for a more secure application, you should consider implementing multi-factor authentication, logging all attempts at privilege escalation, limiting the number of attempts a user can make to escalate their privileges, and regularly reviewing and updating your role configuration settings.

References​

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