attack-tree.md

Attack Tree Analysis for ryanb/cancan

Objective: Compromise Application using CanCan Authorization Weaknesses

Attack Tree Visualization

└── **0. Gain Unauthorized Access/Privileges via CanCan** (Critical Node)
    ├── **1. Exploit Misconfigured Abilities** (High-Risk Path & Critical Node)
    │   ├── **1.1. Overly Permissive Abilities Defined** (High-Risk Path & Critical Node)
    │   │   ├── 1.1.1. Granting `manage` or broad permissions unintentionally
    │   │   ├── 1.1.2. Incorrect Role Assignment leading to elevated privileges
    │   │   ├── 1.1.3. Wildcard permissions (`:all`) used inappropriately
    │   │   └── 1.1.4. Default "guest" or public roles with excessive permissions
    ├── **2. Bypass Authorization Checks in Controllers** (High-Risk Path & Critical Node)
    │   ├── **2.1. Missing `authorize!` or `load_and_authorize_resource` calls** (High-Risk Path & Critical Node)
    │   │   ├── 2.1.1. Direct access to controller actions without authorization
    │   │   └── 2.1.2. Forgetting to authorize specific actions within a controller

Attack Tree Path: 0. Gain Unauthorized Access/Privileges via CanCan (Critical Node)

• Attack Vector: This is the ultimate goal. Attackers aim to exploit any weakness in CanCan implementation to perform actions they are not authorized to do. Success here means compromising application security through authorization bypass.

Attack Tree Path: 1. Exploit Misconfigured Abilities (High-Risk Path & Critical Node)

• Attack Vector: Attackers analyze the Ability class definition (typically app/models/ability.rb). They look for overly broad or incorrectly defined can rules that grant excessive permissions.
  • Example: A rule like can :manage, :all for a non-admin role, or can :update, Article without proper scoping to user ownership.
  • Exploitation: Once identified, attackers leverage these overly permissive rules to access or manipulate resources beyond their intended privileges. This could involve accessing sensitive data, modifying critical application settings, or performing administrative actions.

Attack Tree Path: 1.1. Overly Permissive Abilities Defined (High-Risk Path & Critical Node)

• Attack Vectors (Specific Examples):
  • 1.1.1. Granting manage or broad permissions unintentionally:
    • Attack Vector: Developers might use :manage or broad resource categories (like :all) without fully understanding the implications.
    • Exploitation: An attacker could exploit can :manage, User to modify or delete any user account, or can :manage, :all to control the entire application if assigned to a regular user role.
  • 1.1.2. Incorrect Role Assignment leading to elevated privileges:
    • Attack Vector: Logic flaws in role assignment mechanisms (e.g., vulnerable admin panel, easily guessable role IDs, insecure session management) could allow attackers to manipulate their role.
    • Exploitation: By gaining a role with overly permissive abilities, attackers inherit those permissions and can bypass intended authorization.
  • 1.1.3. Wildcard permissions (:all) used inappropriately:
    • Attack Vector: Using :all as a resource in can definitions grants access to all resources, often unintentionally.
    • Exploitation: can :read, :all grants read access to every resource in the application, potentially exposing sensitive data.
  • 1.1.4. Default "guest" or public roles with excessive permissions:
    • Attack Vector: Default roles (like "guest" or unauthenticated users) might be granted more permissions than necessary.
    • Exploitation: Attackers can exploit these default roles without even needing to authenticate, gaining unauthorized access to features intended for logged-in users.

Attack Tree Path: 2. Bypass Authorization Checks in Controllers (High-Risk Path & Critical Node)

• Attack Vector: Attackers look for controller actions that are not protected by CanCan's authorization checks (authorize! or load_and_authorize_resource). This is a direct bypass of the intended authorization mechanism.
  • Example: A controller action for deleting a user is implemented, but the developer forgets to include authorize! :destroy, @user at the beginning of the action.
  • Exploitation: Attackers can directly access these unprotected controller actions, bypassing CanCan entirely and performing unauthorized operations.

Attack Tree Path: 2.1. Missing authorize! or load_and_authorize_resource calls (High-Risk Path & Critical Node)

• Attack Vectors (Specific Examples):
  • 2.1.1. Direct access to controller actions without authorization:
    • Attack Vector: Developers simply forget to add authorize! or load_and_authorize_resource in controller actions.
    • Exploitation: Attackers can directly send requests to these actions, performing operations without any authorization check.
  • 2.1.2. Forgetting to authorize specific actions within a controller:
    • Attack Vector: A controller might use load_and_authorize_resource for basic CRUD actions, but developers might forget to add explicit authorize! checks for custom or less common actions within the same controller.
    • Exploitation: Attackers can target these un-authorized specific actions, bypassing authorization for those particular functionalities while other parts of the controller might be protected.