mitigations.md

Mitigation Strategies Analysis for octalmage/robotjs

Mitigation Strategy: Strict Input Validation and Sanitization (for robotjs Input)

• Description:

  1. Identify All robotjs Input Points: List every location in your code where data from any source (user input, API responses, configuration files, database reads, etc.) is used, directly or indirectly, as input to any robotjs function (e.g., typeString, keyTap, moveMouse, getPixelColor, screen.capture).
  2. Define Whitelists (per Input Point): For each identified input point, create a precise whitelist of allowed values. This whitelist should be as restrictive as possible, defining the exact acceptable input. Examples:
     • keyTap("enter"): Whitelist is only the string "enter".
     • typeString(username): Whitelist is a regular expression exactly matching valid usernames (e.g., ^[a-zA-Z0-9_]{3,15}$).
     • moveMouse(x, y): Whitelist is a list of valid x, y coordinate pairs.
  3. Implement Validation (Before robotjs Calls): Before any robotjs call, validate the input against the corresponding whitelist. Use a robust validation library. If the input is not in the whitelist, reject it. Do not attempt to "fix" invalid input.
  4. Sanitize (Secondary Defense): Even after validation, perform sanitization as a secondary defense. This might involve escaping special characters. However, rely primarily on whitelisting.
  5. Error Handling (for Rejected Input): When input is rejected, log the event (including the invalid input and the source) and handle the error gracefully. Do not expose detailed error messages to the user.
  6. Centralize Validation (Optional): Consider creating a centralized validation module or function to handle all robotjs input validation.

• Threats Mitigated:

  • Untrusted Input Injection: (Severity: Critical) - Prevents attackers from injecting arbitrary commands or data into robotjs functions.
  • Bypassing Security Controls: (Severity: High) - Makes it harder to bypass UI-based security measures using robotjs.
  • Indirect Privilege Escalation: (Severity: High) - Reduces the risk if the application has elevated privileges.

• Impact:

  • Untrusted Input Injection: Risk reduced from Critical to Low (if implemented correctly).
  • Bypassing Security Controls: Risk reduced from High to Medium.
  • Indirect Privilege Escalation: Risk reduced from High to Medium.

• Currently Implemented:

  • Example: Input validation for the username field in the login function ( /src/auth.js) uses a regular expression.

• Missing Implementation:

  • Example: The processConfig function ( /src/config.js) uses settings from a configuration file with robotjs without validation.
  • Example: The function handleExternalData in /src/api.js uses data from external API and uses it with robotjs.

Mitigation Strategy: Minimize and Restrict Screen Reading (robotjs Specific)

• Description:

  1. Audit getPixelColor and screen.capture Usage: Review all instances of these functions. Document why screen reading is necessary for each.
  2. Explore Alternatives (to Screen Reading): For each instance, investigate if there's a way to achieve the same functionality without reading the screen. Consider APIs, IPC, or OS-level features.
  3. Minimize Capture Area (If Unavoidable): If screen reading is essential, drastically reduce the captured area. Calculate the precise coordinates and dimensions of the smallest possible rectangle needed. Use variables to store these coordinates, ensuring they are not influenced by user input.
  4. Pre-calculate Coordinates (If Fixed): If the target area is fixed, pre-calculate the coordinates and dimensions at development time and store them as constants.
  5. Validate Coordinates (If Dynamic): If coordinates must be calculated dynamically, implement strict validation to ensure they are within safe bounds. Define a maximum allowed size.
  6. Add delays: Add small delays before and after screen reading operations.

• Threats Mitigated:

  • Screen Scraping and Data Exfiltration: (Severity: High) - Reduces the risk of stealing sensitive information from the screen.
  • Indirect Privilege Escalation: (Severity: High) - Reduces risk if the application has elevated privileges.

• Impact:

  • Screen Scraping and Data Exfiltration: Risk reduced from High to Medium (or Low if eliminated).
  • Indirect Privilege Escalation: Risk reduced from High to Medium.

• Currently Implemented:

  • Example: getColorAtLoginButton ( /src/ui_interaction.js) captures only a 10x10 pixel area.

• Missing Implementation:

  • Example: monitorApplicationState ( /src/monitoring.js) captures the entire screen.

Mitigation Strategy: Rate Limiting and Throttling (robotjs Calls)

• Description:

  1. Identify High-Frequency robotjs Calls: Identify all robotjs function calls that could be executed rapidly or repeatedly.
  2. Implement Rate Limiting (per Call): For each identified call, implement rate limiting using techniques like:
     • Token Bucket: Allows a certain number of calls within a time window.
     • Leaky Bucket: Allows calls at a constant rate.
     • Rate-Limiting Libraries: Use a library for your language (e.g., express-rate-limit in Node.js).
  3. Define Appropriate Limits: Determine rate limits based on the legitimate needs of your application. Start restrictively and adjust as needed.
  4. Error Handling (for Rate Limits): When a rate limit is exceeded, log the event and handle the error gracefully (e.g., return an error, temporarily disable functionality, queue the request).
  5. Monitor Usage: Continuously monitor the rate of robotjs calls and adjust limits.
  6. Add delays: Add small delays between robotjs calls.

• Threats Mitigated:

  • Denial of Service (DoS) via Resource Exhaustion: (Severity: Medium) - Prevents overwhelming the system with excessive robotjs calls.
  • Screen Scraping and Data Exfiltration: (Severity: High) - Slows down screen scraping attempts.
  • Bypassing Security Controls: (Severity: High) - Makes rapid automation of security controls more difficult.

• Impact:

  • Denial of Service (DoS): Risk reduced from Medium to Low.
  • Screen Scraping and Data Exfiltration: Risk reduced from High to Medium.
  • Bypassing Security Controls: Risk reduced from High to Medium.

• Currently Implemented:

  • Example: mouseMoveLoop ( /src/animation.js) is limited to 10 calls/second.

• Missing Implementation:

  • Example: typeTextFromAPI ( /src/api_integration.js) types text from an API without rate limiting.

Mitigation Strategy: Avoid Dynamic robotjs Calls (Use Static Calls or Lookup Tables)

• Description:

  1. Identify Dynamic Calls: Find instances where the choice of robotjs function, or its arguments, are determined by user input or external data.
  2. Refactor to Static Calls: If possible, refactor to use static robotjs calls (hardcoded function calls and arguments).
  3. Use a Lookup Table (If Dynamic is Necessary): If dynamic behavior is unavoidable, use a strictly controlled lookup table (e.g., a dictionary or map) or an enum:
     • Keys: Limited set of safe, predefined values (e.g., enum values).
     • Values: Corresponding robotjs function calls and arguments (predefined and safe).
     • User input is used only to select a key from the table. Never construct calls directly from input.
  4. Validate Lookup Key: Before using the table, validate that the user-provided key is a valid key.

• Threats Mitigated:

  • Untrusted Input Injection: (Severity: Critical) - Prevents controlling which robotjs functions are called and with what arguments.
  • Bypassing Security Controls: (Severity: High)
  • Indirect Privilege Escalation: (Severity: High)

• Impact:

  • Untrusted Input Injection: Risk reduced from Critical to Low (if implemented correctly).
  • Bypassing Security Controls: Risk reduced from High to Medium.
  • Indirect Privilege Escalation: Risk reduced from High to Medium.

• Currently Implemented:

  • Example: performAction ( /src/actions.js) uses a lookup table.

• Missing Implementation:

  • Example: executeCommand ( /src/commands.js) takes a command string and uses it directly with robotjs.typeString.