vulnerabilities-workflow-1.md

Vulnerability List

This document outlines the identified vulnerabilities in the application. Each vulnerability is detailed with its description, potential impact, rank, implemented and missing mitigations, preconditions, source code analysis, and a security test case.

1. Lack of Rate Limiting on Authentication Endpoints

Description: The application’s public authentication endpoints—such as the login and password reset views—do not implement any rate‐limiting or brute–force mitigation. An external attacker can automate repeated POST requests against these endpoints. For example, an attacker can script a high volume of login attempts or password reset requests, thereby increasing the likelihood of a successful brute–force attack.

Impact:

• Enables brute–force password guessing that may lead to account compromise.
• Abusing the password reset functionality can result in unauthorized or automated account actions.
• Without throttling, an attacker can try many credential combinations in a short time, greatly increasing the risk of account takeover.

Vulnerability Rank: High

Currently Implemented Mitigations:

• The application uses Django’s built–in authentication, CSRF protection, and secure password checking.
• However, no built–in or custom rate–limiting, CAPTCHA, or account lockout mechanism is applied in methods such as LoginView.form_valid() or PasswordResetView.send_email().

Missing Mitigations:

• Integrate rate limiting or CAPTCHA enforcement on public authentication endpoints.
• Add an account lockout or temporary delay after several failed authentication attempts.

Preconditions:

• The application is deployed with publicly accessible endpoints (for example, /account/login and /account/password/reset), and no external rate–limiting (via a web server or WAF) is configured.

Source Code Analysis:

• In /code/account/views.py, the LoginView class’s form_valid() method immediately logs in the user via self.login_user(form) without checking for a high volume of attempts.
• Similarly, in /code/account/views.py, the PasswordResetView.send_email() method iterates over matching email addresses and sends reset emails on every POST request regardless of frequency.
• Visualization:
  1. An attacker sends a large number of POST requests to /account/login.
  2. Each request is processed normally (using Django’s authentication backend).
  3. No delay or account lockout is triggered, allowing rapid-fire attempts.

Security Test Case:

1. Identify the login endpoint (e.g., https://example.com/account/login).
2. Use an automated tool (such as Burp Suite Intruder) or a custom script to submit a high volume of POST requests with a known username and a list of password guesses.
3. Verify that the server processes each request instantly without any imposed delay or account lockout after repeated failures.
4. Repeat similar tests on /account/password/reset, using the same email address repeatedly.
5. Confirm that no throttling or rate control is enforced by the application.

---

2. User Enumeration via Signup Form Email and Username Validation

Description: In the signup form (located in /code/account/forms.py), the explicit error messages in both clean_username() and clean_email() reveal whether a given username or email already exists in the system. An external attacker can submit requests to the publicly available signup endpoint and distinguish between non–registered and registered values based on the error messages.

Impact:

• Enables attackers to enumerate valid account identifiers (usernames and/or email addresses).
• Information gathered can be used for crafting targeted phishing attacks or for further password–guessing attempts.

Vulnerability Rank: High

Currently Implemented Mitigations:

• The form validations perform case–insensitive database searches and return error messages when duplicates are detected.
• However, the specificity of the error messages (e.g., “This username is already taken” or “A user is registered with this email address”) inadvertently confirms account existence.

Missing Mitigations:

• Use generic error messages that do not disclose whether the username or the email address exists.
• Implement rate limiting on the signup endpoint to slow automated enumeration efforts.

Preconditions:

• The signup form is publicly accessible (for example, at /account/signup).
• An attacker can submit multiple signup requests with different usernames or email addresses and derive account existence from the returned messages.

Source Code Analysis:

• In /code/account/forms.py, the SignupForm.clean_username() method performs a query (via get_user_lookup_kwargs) and then raises a ValidationError with a message like “This username is already taken” when a match is found.
• Similarly, SignupForm.clean_email() checks the EmailAddress model and raises an error if the email is in use.
• Visualization:
  1. An attacker submits a signup request with the email “[email protected]”.
  2. The response returns “A user is registered with this email address.”
  3. The attacker infers that the email is already in use.

Security Test Case:

1. Navigate to the signup page (e.g., https://example.com/account/signup).
2. Submit a signup request using a username or email known to exist.
3. Check that the response contains the explicit error message (e.g., “This username is already taken.” or “A user is registered with this email address.”).
4. Repeat using a list of common usernames or emails to confirm that valid accounts can be enumerated.

---

3. Improper Handling of Signup Code ‘max_uses’ Value Leading to Unlimited Code Reuse

Description: The application uses signup codes (for example, to control access during a private beta). In the SignupCode.create() method (located in /code/account/models.py), the parameter max_uses is set to the provided value—or defaults to 0 if not provided. Later, in the SignupCode.check_code() method, the condition checking whether the maximum allowed uses have been exceeded does not trigger when max_uses is 0 (since 0 is evaluated as falsy). This means that, unless a non–zero value is explicitly provided during creation, a signup code can be reused an unlimited number of times.

Impact:

• An attacker who obtains a signup code (which was intended for a limited use) could repeatedly register new accounts.
• This bypasses the access control mechanism meant to restrict registration (for example, in invitation–only situations).

Vulnerability Rank: High

Currently Implemented Mitigations:

• The database model (per migrations) defines a default value of 1 for max_uses.
• However, the code in SignupCode.create() overrides this by defaulting to 0 when max_uses is not explicitly provided, effectively disabling the usage limit.

Missing Mitigations:

• Modify the SignupCode.create() method to default to a non–zero value (such as 1) when no max_uses is provided.
• Add additional validation to ensure that unintended unlimited–use codes are not generated and to alert developers when such a code is created unintentionally.

Preconditions:

• The attacker must obtain a signup code that was generated using SignupCode.create() without specifying a non–zero max_uses.
• This typically affects environments where signup codes are used to control access.

Source Code Analysis:

• In /code/account/models.py, the class method is defined as follows:

  @classmethod
  def create(cls, **kwargs):
      ...
      params = {
          "code": code,
          "max_uses": kwargs.get("max_uses", 0),
          ...
      }

• When a signup code is created without an explicit max_uses value, it is set to 0.
• Later, the check_code() method contains this check:

  if signup_code.max_uses and signup_code.max_uses <= signup_code.use_count:
      raise cls.InvalidCode()

• Since 0 is falsy, the above condition never invalidates codes with max_uses == 0, allowing unlimited reuse.
• Visualization:
  1. A signup code is generated without an explicit max_uses → max_uses is set to 0.
  2. An attacker uses the same signup code repeatedly without triggering the maximum use limit.

Security Test Case:

1. In a test environment, generate a signup code using SignupCode.create() without specifying a max_uses value.
2. Confirm that the created signup code’s max_uses attribute is 0.
3. Use the signup code to register a new user account via the public signup endpoint.
4. Repeat the registration process multiple times with the same signup code.
5. Verify that the signup code is accepted on every attempt, proving that no usage limit is enforced.