mitigations.md

Mitigation Strategies Analysis for charmbracelet/bubbletea

Mitigation Strategy: Rate Limiting and Throttling of bubbletea Messages

Mitigation Strategy: Rate Limiting and Throttling of bubbletea Messages

• Description:

  1. Identify Message Sources: Within your bubbletea application, identify all sources of tea.Msg values. This includes user input (via tea.KeyMsg, tea.MouseMsg), timer events (tea.Tick), and any custom messages you've defined.
  2. Wrap Messages (Optional): Consider wrapping incoming messages in a custom struct that includes a timestamp:

     type TimedMsg struct {
         Msg tea.Msg
         Time time.Time
     }

  3. Modify Update Function: Within your bubbletea model's Update function, implement the rate limiting/throttling logic:
     • Check Message Type: Use a switch statement to handle different message types.
     • Rate Limiting: For each message type you want to rate limit, maintain a last-processed timestamp. If the current message's timestamp (or the current time, if you're not using TimedMsg) is too close to the last-processed timestamp, return the current model and nil command (effectively dropping the message).
     • Throttling: If you want to throttle instead of drop, store the message in a queue (e.g., a channel). Use a separate goroutine to process messages from the queue at a controlled rate, sending them back to the Update function via a custom message type.
     • Debouncing (for tea.KeyMsg): For keyboard input, implement debouncing within the Update function. Maintain a timer. If a new tea.KeyMsg arrives before the timer expires, reset the timer. Only process the key press if the timer expires.
  4. Return Appropriate Command: Ensure that your Update function always returns a valid tea.Cmd, even if you're dropping or delaying a message. Return nil if no command needs to be executed.
  5. Adjust timing: Adjust timing parameters based on profiling and testing.

• List of Threats Mitigated:

  • Denial of Service (DoS) via Excessive Rendering: Severity: High. Prevents attackers from sending a flood of messages that would overwhelm the bubbletea rendering loop.

• Impact:

  • Denial of Service: Risk reduced from High to Low. The bubbletea application remains responsive even when receiving a high volume of messages.

• Currently Implemented (Hypothetical):

  • No rate limiting or throttling is currently implemented within the Update function.

• Missing Implementation (Hypothetical):

  • All aspects of rate limiting/throttling within the Update function are missing. No logic to handle message frequency is present.

Mitigation Strategy: Robust Panic Handling within bubbletea

Mitigation Strategy: Robust Panic Handling within bubbletea

• Description:

  1. Use tea.WithPanicHandler: When creating your bubbletea program, use the tea.WithPanicHandler option to set a custom panic handler function:

     func myPanicHandler(p interface{}) {
         // Log the panic (including stack trace)
         log.Printf("Panic occurred: %v\n%s", p, debug.Stack())
     
         // Optionally display a user-friendly message in the TUI (if possible)
         // This might involve sending a custom message to the Update function
     
         // Clean up resources (if necessary)
     
         // Exit gracefully
         os.Exit(1)
     }
     
     func main() {
         p := tea.NewProgram(initialModel, tea.WithPanicHandler(myPanicHandler))
         if _, err := p.Run(); err != nil {
             fmt.Printf("Alas, there's been an error: %v", err)
             os.Exit(1)
         }
     }

  2. Handle Panics in Update (Defense in Depth): Even with tea.WithPanicHandler, it's good practice to include a recover block within your Update function as a secondary safety net:

     func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
         defer func() {
             if r := recover(); r != nil {
                 // Log the panic
                 log.Printf("Panic in Update: %v\n%s", r, debug.Stack())
     
                 // Optionally update the model to display an error message
                 m.errorMessage = fmt.Sprintf("An unexpected error occurred: %v", r)
     
                 // Return a command to re-render the view (if appropriate)
             }
         }()
     
         // ... rest of your Update function ...
     }

  3. Avoid panic in bubbletea Code: Within your bubbletea model's Init, Update, and View functions, avoid using panic whenever possible. Use Go's error handling mechanisms (returning error values) to handle expected errors.

• List of Threats Mitigated:

  • Denial of Service (DoS) due to Panics: Severity: Medium. Prevents bubbletea from crashing unexpectedly.
  • Data Leakage due to Panics (Limited): Severity: Low. Reduces the risk of sensitive information being exposed in uncontrolled panic messages.
  • Unexpected Behavior: Severity: Medium. Ensures the bubbletea application exits gracefully.

• Impact:

  • Denial of Service: Risk reduced from Medium to Low.
  • Data Leakage: Risk reduced from Low to Very Low.
  • Unexpected Behavior: Risk reduced from Medium to Low.

• Currently Implemented (Hypothetical):

  • tea.WithPanicHandler is not used.
  • recover is not consistently used within the Update function.

• Missing Implementation (Hypothetical):

  • A custom panic handler using tea.WithPanicHandler is not set.
  • Consistent use of recover within the Update function is missing.

Mitigation Strategy: Safe Terminal Clearing with bubbletea

Mitigation Strategy: Safe Terminal Clearing with bubbletea

• Description:

  1. Use tea.ClearScreen and tea.ClearScrollArea: Before exiting your bubbletea application, use the tea.ClearScreen and tea.ClearScrollArea commands to clear the screen and, to the extent possible, the scrollback area. These are generally more portable than raw escape sequences.

     func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
         switch msg := msg.(type) {
         case tea.KeyMsg:
             if msg.String() == "ctrl+c" {
                 return m, tea.Sequence(tea.ClearScreen, tea.ClearScrollArea, tea.Quit) // Chain commands
             }
         }
         // ... rest of your Update function
     }

  2. Consider Alternate Screen Buffer (with tea.EnterAltScreen and tea.ExitAltScreen): If appropriate for your application, use the alternate screen buffer. bubbletea provides commands for this:

      func main() {
          p := tea.NewProgram(
              initialModel,
              tea.WithAltScreen(), // Enable alternate screen on startup
          )
          if _, err := p.Run(); err != nil {
              fmt.Println("Error running program:", err)
              os.Exit(1)
          }
      }
     
      // OR, manage it manually in Update:
      func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
          switch msg := msg.(type) {
          case tea.KeyMsg:
              if msg.String() == "ctrl+c" {
                  return m, tea.Sequence(tea.ExitAltScreen, tea.Quit)
              }
          }
          // ...
      }

  3. Test on Multiple Terminals: Because terminal behavior varies, thoroughly test your clearing and alternate screen buffer usage on a variety of terminal emulators (e.g., xterm, iTerm2, Windows Terminal, etc.).

• List of Threats Mitigated:

  • Data Leakage via Terminal History/Scrolling: Severity: High. Reduces the risk of sensitive information remaining visible in the terminal after the application exits.

• Impact:

  • Data Leakage: Risk reduced from High to Medium (using tea.ClearScreen and tea.ClearScrollArea) or Low (if the alternate screen buffer is used effectively and supported by the terminal).

• Currently Implemented (Hypothetical):

  • tea.ClearScreen is used, but tea.ClearScrollArea is not.
  • The alternate screen buffer is not used.

• Missing Implementation (Hypothetical):

  • tea.ClearScrollArea is not used.
  • tea.EnterAltScreen and tea.ExitAltScreen (or tea.WithAltScreen) are not used.
  • Testing on a wide range of terminals is not comprehensive.