lib: handle all windows reserved driver name

Signed-off-by: RafaelGSS <rafael.nunu@hotmail.com> PR-URL: nodejs-private/node-private#721 Refs: https://hackerone.com/reports/3160912 CVE-ID: CVE-2025-27210

Author: RafaelGSS

lib/path.js

@@ -22,6 +22,7 @@
 'use strict';
 
 const {
+ ArrayPrototypeIncludes,
  ArrayPrototypeJoin,
  ArrayPrototypeSlice,
  FunctionPrototypeBind,
@@ -34,6 +35,7 @@ const {
  StringPrototypeSlice,
  StringPrototypeSplit,
  StringPrototypeToLowerCase,
+ StringPrototypeToUpperCase,
 } = primordials;
 
 const {
@@ -70,6 +72,17 @@ function isPosixPathSeparator(code) {
  return code === CHAR_FORWARD_SLASH;
 }
 
+const WINDOWS_RESERVED_NAMES = [
+ 'CON', 'PRN', 'AUX', 'NUL',
+ 'COM1', 'COM2', 'COM3', 'COM4', 'COM5', 'COM6', 'COM7', 'COM8', 'COM9',
+ 'LPT1', 'LPT2', 'LPT3', 'LPT4', 'LPT5', 'LPT6', 'LPT7', 'LPT8', 'LPT9',
+];
+
+function isWindowsReservedName(path, colonIndex) {
+ const devicePart = StringPrototypeToUpperCase(StringPrototypeSlice(path, 0, colonIndex));
+ return ArrayPrototypeIncludes(WINDOWS_RESERVED_NAMES, devicePart);
+}
+
 function isWindowsDeviceRoot(code) {
  return (code >= CHAR_UPPERCASE_A && code <= CHAR_UPPERCASE_Z) ||
  (code >= CHAR_LOWERCASE_A && code <= CHAR_LOWERCASE_Z);
@@ -400,16 +413,21 @@ const win32 = {
  } else {
  rootEnd = 1;
  }
- } else if (isWindowsDeviceRoot(code) &&
- StringPrototypeCharCodeAt(path, 1) === CHAR_COLON) {
- // Possible device root
- device = StringPrototypeSlice(path, 0, 2);
- rootEnd = 2;
- if (len > 2 && isPathSeparator(StringPrototypeCharCodeAt(path, 2))) {
- // Treat separator following drive name as an absolute path
- // indicator
- isAbsolute = true;
- rootEnd = 3;
+ } else {
+ const colonIndex = StringPrototypeIndexOf(path, ':');
+ if (colonIndex > 0) {
+ if (isWindowsDeviceRoot(code) && colonIndex === 1) {
+ device = StringPrototypeSlice(path, 0, 2);
+ rootEnd = 2;
+ if (len > 2 && isPathSeparator(StringPrototypeCharCodeAt(path, 2))) {
+ isAbsolute = true;
+ rootEnd = 3;
+ }
+ } else if (isWindowsReservedName(path, colonIndex)) {
+ device = StringPrototypeSlice(path, 0, colonIndex + 1);
+ rootEnd = colonIndex + 1;
+
+ }
  }
  }
 
@@ -433,12 +451,17 @@ const win32 = {
  return `.\\${tail}`;
  }
  let index = StringPrototypeIndexOf(path, ':');
+
  do {
  if (index === len - 1 || isPathSeparator(StringPrototypeCharCodeAt(path, index + 1))) {
  return `.\\${tail}`;
  }
  } while ((index = StringPrototypeIndexOf(path, ':', index + 1)) !== -1);
  }
+ const colonIndex = StringPrototypeIndexOf(path, ':');
+ if (isWindowsReservedName(path, colonIndex)) {
+ return `.\\${device ?? ''}${tail}`;
+ }
  if (device === undefined) {
  return isAbsolute ? `\\${tail}` : tail;
  }

test/parallel/test-path-win32-normalize-device-names.js

@@ -0,0 +1,98 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const path = require('path');
+
+if (!common.isWindows) {
+ common.skip('Windows only');
+}
+
+const normalizeDeviceNameTests = [
+ { input: 'CON', expected: 'CON' },
+ { input: 'con', expected: 'con' },
+ { input: 'CON:', expected: '.\\CON:.' },
+ { input: 'con:', expected: '.\\con:.' },
+ { input: 'CON:.', expected: '.\\CON:.' },
+ { input: 'coN:', expected: '.\\coN:.' },
+ { input: 'LPT9.foo', expected: 'LPT9.foo' },
+ { input: 'COM9:', expected: '.\\COM9:.' },
+ { input: 'COM9.', expected: '.\\COM9.' },
+ { input: 'C:COM9', expected: 'C:COM9' },
+ { input: 'C:\\COM9', expected: 'C:\\COM9' },
+ { input: 'CON:./foo', expected: '.\\CON:foo' },
+ { input: 'CON:/foo', expected: '.\\CON:foo' },
+ { input: 'CON:../foo', expected: '.\\CON:..\\foo' },
+ { input: 'CON:/../foo', expected: '.\\CON:..\\foo' },
+ { input: 'CON:./././foo', expected: '.\\CON:foo' },
+ { input: 'CON:..', expected: '.\\CON:..' },
+ { input: 'CON:..\\', expected: '.\\CON:..\\' },
+ { input: 'CON:..\\..', expected: '.\\CON:..\\..' },
+ { input: 'CON:..\\..\\', expected: '.\\CON:..\\..\\' },
+ { input: 'CON:..\\..\\foo', expected: '.\\CON:..\\..\\foo' },
+ { input: 'CON:..\\..\\foo\\', expected: '.\\CON:..\\..\\foo\\' },
+ { input: 'CON:..\\..\\foo\\bar', expected: '.\\CON:..\\..\\foo\\bar' },
+ { input: 'CON:..\\..\\foo\\bar\\', expected: '.\\CON:..\\..\\foo\\bar\\' },
+ { input: 'COM1:a:b:c', expected: '.\\COM1:a:b:c' },
+ { input: 'COM1:a:b:c/', expected: '.\\COM1:a:b:c\\' },
+ { input: 'c:lpt1', expected: 'c:lpt1' },
+ { input: 'c:\\lpt1', expected: 'c:\\lpt1' },
+
+ // Reserved device names with path traversal
+ { input: 'CON:.\\..\\..\\foo', expected: '.\\CON:..\\..\\foo' },
+ { input: 'PRN:.\\..\\bar', expected: '.\\PRN:..\\bar' },
+ { input: 'AUX:/../../baz', expected: '.\\AUX:..\\..\\baz' },
+
+ { input: 'COM1:', expected: '.\\COM1:.' },
+ { input: 'COM9:', expected: '.\\COM9:.' },
+ { input: 'COM1:.\\..\\..\\foo', expected: '.\\COM1:..\\..\\foo' },
+ { input: 'LPT1:', expected: '.\\LPT1:.' },
+ { input: 'LPT9:', expected: '.\\LPT9:.' },
+ { input: 'LPT1:.\\..\\..\\foo', expected: '.\\LPT1:..\\..\\foo' },
+ { input: 'LpT5:/another/path', expected: '.\\LpT5:another\\path' },
+
+ { input: 'C:\\foo', expected: 'C:\\foo' },
+ { input: 'D:bar', expected: 'D:bar' },
+
+ { input: 'CON', expected: 'CON' },
+ { input: 'CON.TXT', expected: 'CON.TXT' },
+ { input: 'COM10:', expected: '.\\COM10:' },
+ { input: 'LPT10:', expected: '.\\LPT10:' },
+ { input: 'CONNINGTOWER:', expected: '.\\CONNINGTOWER:' },
+ { input: 'AUXILIARYDEVICE:', expected: '.\\AUXILIARYDEVICE:' },
+ { input: 'NULLED:', expected: '.\\NULLED:' },
+ { input: 'PRNINTER:', expected: '.\\PRNINTER:' },
+
+ { input: 'CON:\\..\\..\\windows\\system32', expected: '.\\CON:..\\..\\windows\\system32' },
+ { input: 'PRN:.././../etc/passwd', expected: '.\\PRN:..\\..\\etc\\passwd' },
+
+ // Test with trailing slashes
+ { input: 'CON:\\', expected: '.\\CON:.\\' },
+ { input: 'COM1:\\foo\\bar\\', expected: '.\\COM1:foo\\bar\\' },
+
+ // Test cases from original vulnerability reports or similar scenarios
+ { input: 'COM1:.\\..\\..\\foo.js', expected: '.\\COM1:..\\..\\foo.js' },
+ { input: 'LPT1:.\\..\\..\\another.txt', expected: '.\\LPT1:..\\..\\another.txt' },
+
+ // Paths with device names not at the beginning
+ { input: 'C:\\CON', expected: 'C:\\CON' },
+ { input: 'C:\\path\\to\\COM1:', expected: 'C:\\path\\to\\COM1:' },
+
+ // Device name followed by multiple colons
+ { input: 'CON::', expected: '.\\CON::' },
+ { input: 'COM1:::foo', expected: '.\\COM1:::foo' },
+
+ // Device name with mixed path separators
+ { input: 'AUX:/foo\\bar/baz', expected: '.\\AUX:foo\\bar\\baz' },
+];
+
+for (const { input, expected } of normalizeDeviceNameTests) {
+ const actual = path.win32.normalize(input);
+ assert.strictEqual(actual, expected,
+ `path.win32.normalize(${JSON.stringify(input)}) === ${JSON.stringify(expected)}, but got ${JSON.stringify(actual)}`);
+}
+
+assert.strictEqual(path.win32.normalize('CON:foo/../bar'), '.\\CON:bar');
+
+// This should NOT be prefixed because 'c:' is treated as a drive letter.
+assert.strictEqual(path.win32.normalize('c:COM1:'), 'c:COM1:');