fix(security): enforce case-insensitive sensitive path blocklist and vscode hitl (#27966)

Co-authored-by: David Pierce <davidapierce@google.com>

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

@@ -492,4 +492,50 @@ describe('WorkspaceContext with optional directories', () => {
     expect(directories).toEqual([cwd, existingDir1]);
     expect(debugLogger.warn).not.toHaveBeenCalled();
   });
+
+  describe('Security Regression: Case-Insensitive Sensitive Path Blocklist', () => {
+    it('should reject sensitive paths like .git, .env, and node_modules case-insensitively, including Windows trailing character and NTFS ADS bypasses', () => {
+      const workspaceContext = new WorkspaceContext(cwd);
+
+      const sensitivePaths = [
+        path.join(cwd, '.git', 'config'),
+        path.join(cwd, '.GIT', 'config'),
+        path.join(cwd, '.Git', 'config'),
+        path.join(cwd, '.env'),
+        path.join(cwd, '.Env'),
+        path.join(cwd, '.ENV'),
+        path.join(cwd, 'node_modules', 'package', 'index.js'),
+        path.join(cwd, 'NODE_MODULES', 'package', 'index.js'),
+        // Windows trailing character bypasses
+        path.join(cwd, '.git ', 'config'),
+        path.join(cwd, '.git.', 'config'),
+        path.join(cwd, '.env ', 'config'),
+        path.join(cwd, '.env.', 'config'),
+        path.join(cwd, 'node_modules ', 'package', 'index.js'),
+        // NTFS Alternate Data Stream bypasses
+        path.join(cwd, '.git::$DATA', 'config'),
+        path.join(cwd, '.env::$DATA'),
+        path.join(cwd, 'node_modules::$DATA', 'package', 'index.js'),
+      ];
+
+      for (const p of sensitivePaths) {
+        expect(workspaceContext.isPathWithinWorkspace(p)).toBe(false);
+      }
+    });
+
+    it('should allow standard non-sensitive paths', () => {
+      const workspaceContext = new WorkspaceContext(cwd);
+
+      const safePaths = [
+        path.join(cwd, 'src', 'index.ts'),
+        path.join(cwd, '.gitignore'),
+        path.join(cwd, '.env.example'),
+        path.join(cwd, 'package.json'),
+      ];
+
+      for (const p of safePaths) {
+        expect(workspaceContext.isPathWithinWorkspace(p)).toBe(true);
+      }
+    });
+  });
 });

packages/core/src/utils/workspaceContext.ts

@@ -184,6 +184,20 @@ export class WorkspaceContext {
 
       for (const dir of this.directories) {
         if (this.isPathWithinRoot(fullyResolvedPath, dir)) {
+          // Check for blocked segments case-insensitively
+          const relative = path.relative(dir, fullyResolvedPath);
+          const segments = relative.split(path.sep);
+          const hasBlockedSegment = segments.some((segment) => {
+            const clean = trimTrailingSpacesAndDots(
+              segment.split(':')[0],
+            ).toLowerCase();
+            return (
+              clean === '.git' || clean === '.env' || clean === 'node_modules'
+            );
+          });
+          if (hasBlockedSegment) {
+            return false;
+          }
           return true;
         }
       }
@@ -248,3 +262,15 @@ export class WorkspaceContext {
     );
   }
 }
+
+/**
+ * Trims trailing spaces and dots from a string without using regular expressions
+ * to completely eliminate any potential ReDoS (Regular Expression Denial of Service) risk.
+ */
+function trimTrailingSpacesAndDots(str: string): string {
+  let end = str.length - 1;
+  while (end >= 0 && (str[end] === ' ' || str[end] === '.')) {
+    end--;
+  }
+  return str.slice(0, end + 1);
+}