🛡️ fix: Enhance File Upload Security & Error Handling (#4705)

* fix: sanitize filename in multer storage callback

* fix: ensure temporary image upload file is deleted after processing

* fix: prevent cleanup flag from being set to false before actually deleted

* refactor: user avatar, typing, use 'file' for formData instead of 'input', add disk storage, use localization

* fix: update Avatar component to include image dimensions in formData and refactor editor reference type

* fix: refactor avatar upload handling to use fs for file reading and enhance file validation

* fix: ensure temporary image upload file is deleted after processing

* fix: refactor avatar upload routes and handlers for agents and assistants, improve file handling and validation

* fix: improve audio file validation and cleanup

* fix: add filename sanitization utility and integrate it into multer storage configuration

* fix: update group project ID check for null and refactor delete prompt group response type

* fix: invalid access control for deleting prompt groups

* fix: add error handling and logging to checkBan middleware

* fix: catch conversation parsing errors

* chore: revert unnecessary height and width parameters from avatar upload

* chore: update librechat-data-provider version to 0.7.55

* style: ensure KaTeX can spread across visible space

api/server/utils/handleText.spec.js

@@ -1,4 +1,4 @@
-const { isEnabled } = require('./handleText');
+const { isEnabled, sanitizeFilename } = require('./handleText');
 
 describe('isEnabled', () => {
   test('should return true when input is "true"', () => {
@@ -49,3 +49,51 @@ describe('isEnabled', () => {
     expect(isEnabled([])).toBe(false);
   });
 });
+
+jest.mock('crypto', () => ({
+  randomBytes: jest.fn().mockReturnValue(Buffer.from('abc123', 'hex')),
+}));
+
+describe('sanitizeFilename', () => {
+  test('removes directory components (1/2)', () => {
+    expect(sanitizeFilename('/path/to/file.txt')).toBe('file.txt');
+  });
+
+  test('removes directory components (2/2)', () => {
+    expect(sanitizeFilename('../../../../file.txt')).toBe('file.txt');
+  });
+
+  test('replaces non-alphanumeric characters', () => {
+    expect(sanitizeFilename('file name@#$.txt')).toBe('file_name___.txt');
+  });
+
+  test('preserves dots and hyphens', () => {
+    expect(sanitizeFilename('file-name.with.dots.txt')).toBe('file-name.with.dots.txt');
+  });
+
+  test('prepends underscore to filenames starting with a dot', () => {
+    expect(sanitizeFilename('.hiddenfile')).toBe('_.hiddenfile');
+  });
+
+  test('truncates long filenames', () => {
+    const longName = 'a'.repeat(300) + '.txt';
+    const result = sanitizeFilename(longName);
+    expect(result.length).toBe(255);
+    expect(result).toMatch(/^a+-abc123\.txt$/);
+  });
+
+  test('handles filenames with no extension', () => {
+    const longName = 'a'.repeat(300);
+    const result = sanitizeFilename(longName);
+    expect(result.length).toBe(255);
+    expect(result).toMatch(/^a+-abc123$/);
+  });
+
+  test('handles empty input', () => {
+    expect(sanitizeFilename('')).toBe('_');
+  });
+
+  test('handles input with only special characters', () => {
+    expect(sanitizeFilename('@#$%^&*')).toBe('_______');
+  });
+});