Skip to content

Latest commit

 

History

History
88 lines (68 loc) · 7.91 KB

mitigations.md

File metadata and controls

88 lines (68 loc) · 7.91 KB

Mitigation Strategies Analysis for teamcapybara/capybara

Mitigation Strategy: 1. Input Sanitization in Test Data (Capybara Interaction)

  • Description:

    1. Within your Capybara test code, identify all methods that simulate user input, specifically: fill_in, choose, select, attach_file, and any custom methods built on top of these. Also, critically examine any use of execute_script or evaluate_script that directly manipulates the DOM.
    2. For every instance of these methods, analyze the data being passed as input.
    3. If the input data contains any characters that could be interpreted as HTML or JavaScript (e.g., <, >, &, ", ', /, (, ), =, etc.), or if it resembles code, it must be sanitized before being passed to the Capybara method.
    4. Use a dedicated sanitization library (like the sanitize gem in Ruby). Do not rely solely on the application's input validation.
    5. Call the sanitization function (e.g., Sanitize.fragment(input)) and use the returned, sanitized value as the input to the Capybara method. Example: 
      # UNSAFE:
fill_in "comment", with: "<script>alert('XSS')</script>"

# SAFE:
require 'sanitize'
malicious_input = "<script>alert('XSS')</script>"
sanitized_input = Sanitize.fragment(malicious_input)
fill_in "comment", with: sanitized_input
    6. Regularly review test code for new uses of input methods and ensure sanitization is applied consistently.

  • Threats Mitigated:

    • Test-Induced XSS (High Severity): Capybara, by interacting with the browser, can create XSS vulnerabilities during the test run if unsanitized input is used. This is a direct threat from Capybara's operation.
    • Masked Application XSS (High Severity): If the test data itself contains XSS payloads, it might trigger the application's existing defenses, leading to a false negative (the test passes, but a real vulnerability remains).
    • Data Corruption (Medium Severity): Unsanitized input could, in some cases, lead to data corruption if the application's input validation is flawed, and Capybara bypasses client-side checks.

  • Impact:

    • Test-Induced XSS: Risk reduced from High to Very Low.
    • Masked Application XSS: Risk reduced from High to Low (assuming the application also sanitizes input).
    • Data Corruption: Risk reduced from Medium to Low.

  • Currently Implemented: Partially. Sanitization is used in some feature specs, but not consistently.

  • Missing Implementation: Missing in several older specs and in helper methods that generate test data. A consistent, project-wide policy is needed.

Mitigation Strategy: 2. Avoid execute_script and evaluate_script (Capybara-Specific Risk)

  • Description:

    1. Thoroughly review all Capybara test files.
    2. Identify every instance of execute_script and evaluate_script.
    3. For each instance, critically assess if the same functionality can be achieved using Capybara's built-in methods (e.g., fill_in, click_on, find, have_selector, have_content, etc.). These built-in methods are designed to interact with the page in a safer, more controlled way.
    4. If a built-in Capybara method can achieve the desired result, refactor the test to use it.
    5. If execute_script or evaluate_script is absolutely, demonstrably unavoidable, treat the script string exactly like user input. Apply rigorous sanitization (as detailed in Mitigation #1) to the script string before passing it to these methods. Document in detail why the built-in methods were insufficient.
    6. Implement a code review policy that requires explicit justification and sanitization for any new use of execute_script or evaluate_script.

  • Threats Mitigated:

    • Test-Induced XSS (High Severity): execute_script and evaluate_script are the most direct ways to inject arbitrary JavaScript into the page during a test, creating a high-risk XSS vulnerability. This is a direct consequence of using these Capybara methods.
    • Bypassing Application Defenses (Medium Severity): These methods can bypass client-side validation and security mechanisms, potentially masking real vulnerabilities in the application.
    • Unintended Side Effects (Low Severity): Direct JavaScript execution can have unpredictable and difficult-to-debug side effects, making tests less reliable and potentially affecting the application state.

  • Impact:

    • Test-Induced XSS: Risk reduced from High to Low (provided sanitization is always applied when these methods are unavoidable).
    • Bypassing Application Defenses: Risk reduced from Medium to Low.
    • Unintended Side Effects: Risk reduced from Low to Very Low.

  • Currently Implemented: Mostly. A conscious effort has been made to minimize their use, and developers are generally aware of the risks.

  • Missing Implementation: Some older test files still use these methods without proper sanitization or justification. A stricter code review policy is needed.

Mitigation Strategy: 3. Use Capybara's Waiting Mechanisms (Preventing Timing-Related Issues)

  • Description:

    1. Review all Capybara test files.
    2. Identify any instances of sleep or fixed-time delays. These are almost always incorrect in Capybara tests.
    3. Replace all instances of sleep with Capybara's built-in waiting methods:
      • expect(page).to have_selector(...): Waits for an element matching the CSS selector to appear.
      • expect(page).to have_content(...): Waits for the specified text to appear within the page content.
      • expect(page).to have_no_selector(...): Waits for an element matching the selector to disappear.
      • expect(page).to have_current_path(...): Waits for the browser's current URL to match the given path.
      • wait_until { ... }: Waits until the provided Ruby block returns a truthy value. This is a more general-purpose waiting mechanism.
    4. Use appropriate timeouts with these waiting methods. Start with Capybara's default timeout (Capybara.default_max_wait_time) and adjust only if necessary.
    5. If timing issues persist after using the appropriate waiting methods, then consider increasing Capybara.default_max_wait_time as a last resort, and document why this was necessary.

  • Threats Mitigated:

    • False Negatives (Medium Severity): Prevents tests from passing when the application is actually broken due to timing issues. For example, a test might check for an element before it's fully loaded by JavaScript, leading to a false negative (the test passes, but a vulnerability related to that element might exist). This is a direct result of how Capybara interacts with asynchronous web applications.
    • False Positives (Low Severity): Prevents tests from failing when the application is working correctly, but simply taking slightly longer than a fixed sleep duration.
    • Flaky Tests (Low Severity): Reduces the likelihood of tests failing intermittently due to variations in network latency, server response time, or browser rendering speed.

  • Impact:

    • False Negatives: Risk reduced from Medium to Low.
    • False Positives: Risk reduced from Low to Very Low.
    • Flaky Tests: Risk reduced from Low to Very Low.

  • Currently Implemented: Mostly. Most tests use Capybara's waiting mechanisms correctly.

  • Missing Implementation: A few older tests still rely on sleep in some places. These need to be refactored to use the appropriate waiting methods.