Need

Proper configuration and assignment of roles to ensure accurate representation of security responsibilities

Context

• Usage of Python 3 for building and running Python applications
• Usage of Django for building web applications

Description

Non compliant code

        from django.contrib.auth.models import User, Group

def create_roles():
    # Create Users
    user1 = User.objects.create_user(username='user1', password='password')
    user2 = User.objects.create_user(username='user2', password='password')

    # Create Group
    group = Group.objects.create(name='Admin')

    # Add users to the group
    group.user_set.add(user1, user2)
        
        

In this code, we are creating two users and assigning them to the same group, which is named 'Admin'. This is a security vulnerability because it does not correctly represent the different aspects of responsibilities for the security levels of the organization.

The problem arises from the fact that all users in the 'Admin' group have the same level of access and permissions, irrespective of their actual roles and responsibilities within the organization. This could potentially allow a user to perform actions that they should not be able to, leading to unauthorized access or modification of data.

In a more secure setup, we would have different groups for different roles, each with their own set of permissions. This way, users can only perform actions that are within their role's responsibilities, preventing potential security breaches.

Steps

• Define clear roles and responsibilities for each user group in the system.
• Create separate groups for different roles such as 'Admin', 'User', 'Guest' etc.
• Assign appropriate permissions to each group according to their roles and responsibilities.
• Ensure that users are added to the correct group according to their role.
• Implement a mechanism to regularly review and update the roles and permissions of each group.
• Use strong, unique passwords for each user and store them securely.
• Implement a mechanism to regularly update the user's passwords.

Compliant code

        from django.contrib.auth.models import User, Group, Permission
from django.contrib.contenttypes.models import ContentType
from myapp.models import MyModel

def create_roles():
    # Create Users with unique and strong passwords
    user1 = User.objects.create_user(username='user1', password='strongpassword1')
    user2 = User.objects.create_user(username='user2', password='strongpassword2')

    # Create Groups
    admin_group = Group.objects.create(name='Admin')
    user_group = Group.objects.create(name='User')
    guest_group = Group.objects.create(name='Guest')

    # Define permissions for each group
    content_type = ContentType.objects.get_for_model(MyModel)

    # Admin permissions
    can_add = Permission.objects.create(codename='can_add_mymodel',
                                        name='Can add my model',
                                        content_type=content_type)
    can_change = Permission.objects.create(codename='can_change_mymodel',
                                           name='Can change my model',
                                           content_type=content_type)
    can_delete = Permission.objects.create(codename='can_delete_mymodel',
                                           name='Can delete my model',
                                           content_type=content_type)

    admin_group.permissions.set([can_add, can_change, can_delete])

    # User permissions
    user_group.permissions.set([can_add, can_change])

    # Guest permissions
    guest_group.permissions.set([can_add])

    # Add users to the correct group according to their role
    admin_group.user_set.add(user1)
    user_group.user_set.add(user2)
        
        

The updated code creates three different user groups: 'Admin', 'User', and 'Guest'. Each group is assigned specific permissions according to their roles and responsibilities.

The 'Admin' group has permissions to add, change, and delete instances of 'MyModel'. The 'User' group can add and change instances, but not delete them. The 'Guest' group can only add instances.

The users 'user1' and 'user2' are created with unique and strong passwords. 'user1' is added to the 'Admin' group and 'user2' is added to the 'User' group.

This setup ensures that each user has the appropriate permissions according to their role, enhancing the security of the system. Regular reviews and updates of roles and permissions should be implemented to maintain this security.

References

• 319. Insecure service configuration - Roles