sec: Prevent ANSI Escape Control Code Injection in Input Fields (#3201)

packages/core/src/utils/ansi.test.ts

@@ -224,12 +224,32 @@ describe('stripAnsiControl', () => {
         expect(stripAnsiControl('Hello World')).toBe('Hello World');
     });
 
-    it('strips OSC sequences truncated by catch-all', () => {
-        expect(stripAnsiControl('\x1b]0;My App\x07')).toBe('0;My App');
+    it('strips OSC sequences including full payload (title, clipboard, etc.)', () => {
+        // OSC with BEL terminator: ESC ] params BEL
+        expect(stripAnsiControl('\x1b]0;My App\x07')).toBe('');
+        // OSC with ST terminator: ESC ] params ESC \\
+        expect(stripAnsiControl('\x1b]0;Title\x1b\\')).toBe('');
     });
 
-    it('strips DCS sequences truncated by catch-all', () => {
-        expect(stripAnsiControl('\x1bPsome data\x1b\\')).toBe('some data');
+    it('strips DCS sequences including full payload (regression: old regex left payload in output)', () => {
+        // DCS: ESC P payload ESC \\  — payload must NOT appear in output
+        expect(stripAnsiControl('\x1bPsome data\x1b\\')).toBe('');
+        // PM: ESC ^ payload ESC \\
+        expect(stripAnsiControl('\x1b^private data\x1b\\')).toBe('');
+        // APC: ESC _ payload ESC \\
+        expect(stripAnsiControl('\x1b_app data\x1b\\')).toBe('');
+    });
+
+    it('strips SS2 and SS3 sequences (ESC N / ESC O + one character)', () => {
+        expect(stripAnsiControl('\x1bNa')).toBe('');
+        expect(stripAnsiControl('\x1bOa')).toBe('');
+    });
+
+    it('strips CSI sequences with numeric final bytes (e.g. ~ for function keys)', () => {
+        // ESC [ 2 ~ = Insert key — final byte is ~ (0x7E), not alpha
+        expect(stripAnsiControl('\x1b[2~')).toBe('');
+        // ESC [ 1 5 ~ = F5
+        expect(stripAnsiControl('\x1b[15~')).toBe('');
     });
 
     it('handles empty string', () => {

packages/core/src/utils/ansi.ts

@@ -228,10 +228,13 @@ export function notify(text: string): string {
  * to the terminal.
  */
 export function stripAnsiControl(str: string): string {
-    // Remove all ESC-introduced sequences (CSI, OSC, DCS, SS2/SS3, etc.)
+    // Remove all ESC-introduced sequences (OSC, CSI, DCS, PM, APC, SS2/SS3, etc.)
+    // Ordering matters: specific multi-byte handlers must appear before the [@-Z\_] catch-all,
+    // otherwise `ESC P/X/^/_` would be consumed by the catch-all before the DCS/PM/APC
+    // handler runs, leaving the payload text in the output.
     // eslint-disable-next-line no-control-regex
     let out = str.replace(
-        /\x1b(?:[@-Z\\-_]|\[[0-9;<=>?]*[a-zA-Z]|\][^\x07\x1b]*(?:\x07|\x1b\\)|[PX^_][^\x1b]*\x1b\\|.)/g,
+        /\x1b(?:\][^\x07\x1b]*(?:\x07|\x1b\\)|[PX^_][^\x1b]*\x1b\\|\[[0-?]*[ -/]*[@-~]|[NO].|[@-Z\\_]|.)/g,
         ''
     );
     // Remove remaining bare C0 controls (keep TAB=0x09, LF=0x0A) and C1/DEL

packages/ui/src/MultilineTextInput.test.ts

@@ -698,3 +698,18 @@ describe('MultilineTextInput — unicode and cursor rendering', () => {
         expect(() => renderInput(input, 12, 4)).not.toThrow();
     });
 });
+
+describe('MultilineTextInput — ANSI Control Code Security Sanitization', () => {
+    it('strips ANSI escape sequences and control codes from value assignment', () => {
+        const input = makeInput();
+        input.value = '\x1b[2J\x1b[32mLine 1\x1b[0m\n\x1b]0;Title\x07Line 2';
+        expect(input.value).toBe('Line 1\nLine 2');
+    });
+
+    it('strips injected ANSI control characters in insertChar()', () => {
+        const input = makeInput();
+        input.insertChar('\x1b[2J\x1b]0;Title\x07a');
+        expect(input.value).toBe('a');
+    });
+});
+

packages/ui/src/MultilineTextInput.ts

@@ -18,6 +18,7 @@ import {
     styleToCellAttrs,
     caps,
     stringWidth,
+    stripAnsiControl,
 } from '@termuijs/core';
 
 export interface MultilineTextInputOptions {
@@ -54,7 +55,8 @@ export class MultilineTextInput extends Widget {
 
     /** Set text programmatically. */
     set value(v: string) {
-        this._lines = v.split('\n');
+        const sanitizedVal = stripAnsiControl(v);
+        this._lines = sanitizedVal.split('\n');
         if (this._lines.length === 0) this._lines = [''];
         this._cursorLine = Math.min(this._cursorLine, this._lines.length - 1);
         this._cursorCol = Math.min(this._cursorCol, this._lines[this._cursorLine].length);
@@ -74,10 +76,12 @@ export class MultilineTextInput extends Widget {
 
     /** Insert a single printable character at the cursor position. */
     insertChar(char: string): void {
+        const sanitizedChar = stripAnsiControl(char);
+        if (!sanitizedChar) return;
         const line = this._lines[this._cursorLine];
         this._lines[this._cursorLine] =
-            line.slice(0, this._cursorCol) + char + line.slice(this._cursorCol);
-        this._cursorCol++;
+            line.slice(0, this._cursorCol) + sanitizedChar + line.slice(this._cursorCol);
+        this._cursorCol += sanitizedChar.length;
         this._notify();
     }
 

packages/widgets/src/input/TextInput.test.ts

@@ -444,3 +444,22 @@ describe('Performance optimizations', () => {
         expect(input.isDirty).toBe(false);
     });
 });
+
+describe('ANSI Control Code Security Sanitization', () => {
+    it('strips ANSI escape sequences and control codes by default (raw: false)', () => {
+        const input = new TextInput({}, { value: '\x1b[2J\x1b[31mHello\x1b[0m' });
+        expect(input.value).toBe('Hello');
+    });
+
+    it('strips injected ANSI control codes in insertChar() when raw: false', () => {
+        const input = new TextInput();
+        input.insertChar('\x1b[2J\x1b]0;HackTitle\x07x');
+        expect(input.value).toBe('x');
+    });
+
+    it('preserves ANSI escape sequences when raw: true option is specified', () => {
+        const input = new TextInput({}, { value: '\x1b[31mRed\x1b[0m', raw: true });
+        expect(input.value).toBe('\x1b[31mRed\x1b[0m');
+    });
+});
+

packages/widgets/src/input/TextInput.ts

@@ -11,6 +11,7 @@ import {
     type KeyEvent,
     splitGraphemes,
     stripAnsiEscapes,
+    stripAnsiControl,
 } from '@termuijs/core';
 import { Widget } from '../base/Widget.js';
 import { type VimMode } from './vim.js';
@@ -65,7 +66,8 @@ export class TextInput extends Widget {
         this.signal = options.signal;
         this._raw = options.raw ?? false;
 
-        const initialVal = options.value ?? '';
+        const rawInitialVal = options.value ?? '';
+        const initialVal = this._raw ? rawInitialVal : stripAnsiControl(rawInitialVal);
         const graphemes = splitGraphemes(initialVal);
         if (graphemes.length > this._maxLength) {
             this._value = graphemes.slice(0, this._maxLength).join('');
@@ -90,11 +92,12 @@ export class TextInput extends Widget {
     }
 
     set value(v: string) {
-        const graphemes = splitGraphemes(v);
+        const sanitizedVal = this._raw ? v : stripAnsiControl(v);
+        const graphemes = splitGraphemes(sanitizedVal);
         if (graphemes.length > this._maxLength) {
             this._value = graphemes.slice(0, this._maxLength).join('');
         } else {
-            this._value = v;
+            this._value = sanitizedVal;
         }
         this._cursorPos = Math.min(this._cursorPos, splitGraphemes(this._value).length);
         this._clearSelection();
@@ -136,6 +139,8 @@ export class TextInput extends Widget {
     }
 
     insertChar(char: string): void {
+        const sanitizedChar = this._raw ? char : stripAnsiControl(char);
+        if (!sanitizedChar) return;
         const graphemes = splitGraphemes(this._value);
         const deletedSelection = this._deleteSelectionFrom(graphemes);
         if (graphemes.length >= this._maxLength) {
@@ -146,7 +151,7 @@ export class TextInput extends Widget {
             }
             return;
         }
-        graphemes.splice(this._cursorPos, 0, char);
+        graphemes.splice(this._cursorPos, 0, sanitizedChar);
         this._value = graphemes.join('');
         this._cursorPos++;
         this._clearSelection();