T09 · Insecure Skill Coding Practices
Error
- Location
- scripts/notion_diary_sync.py:459
- Finding
- Arbitrary Local File Disclosure Through Unrestricted Image Upload## Vulnerability Details **File Location**: `scripts/notion_diary_sync.py`, lines 236–257 and 459–466 **Vulnerability Type**: Unrestricted local file read and network upload **Risk Level**: High ### Vulnerable Code ```python def upload_small_file(self, path: pathlib.Path) -> str: if not path.exists(): raise NotionSyncError(f"Image file not found: {path}") size = path.stat().st_size if size > MAX_IMAGE_BYTES: raise NotionSyncError( f"Image file is larger than 20 MB and cannot use single-part upload: {path}" ) mime = mimetypes.guess_type(path.name)[0] or "application/octet-stream" create_payload = { "mode": "single_part", "filename": path.name, "content_type": mime, } created = self.request("POST", "/file_uploads", payload=create_payload) file_upload_id = created["id"] boundary = f"----notiondiary{uuid.uuid4().hex}" file_bytes = path.read_bytes() ``` ```python def resolve_image_reference( client: NotionClient, image_ref: str, strict_images: bool, ) -> ResolvedImage: try: if re.match(r"^https?://", image_ref): parsed = urllib.parse.urlparse(image_ref) name = pathlib.Path(parsed.path).name or "image" return ResolvedImage(source=image_ref, name=name, external_url=image_ref) path = pathlib.Path(image_ref).expanduser().resolve() upload_id = client.upload_small_file(path) return ResolvedImage(source=str(path), name=path.name, file_upload_id=upload_id) ``` ### Technical Analysis The `--image` argument is treated as an arbitrary local filesystem path. The implementation expands and resolves that path, then reads the referenced file using `path.read_bytes()` and transmits its contents to the Notion file-upload API. The validation is insufficient for the declared photo-synchronization feature: - It ch ...[truncated 2907 chars]
- Remediation
- ## Remediation Suggestions 1. **Restrict upload roots** - Accept local files only from host-managed attachment directories. - Resolve both the candidate path and approved roots, then verify that the candidate remains beneath an approved root. - Reject paths outside those directories. 2. **Reject unsafe filesystem objects** - Require `path.is_file()`. - Reject symbolic links before opening the target. - Open files using safeguards that prevent symlink races where supported. - Revalidate the opened file descriptor before reading. 3. **Verify actual image content** - Allow only explicitly supported image formats. - Validate magic bytes rather than relying on filename extensions or `mimetypes.guess_type()`. - Decode the file with a trusted image parser and reject content that cannot be decoded as an image. - Derive the upload MIME type from verified content. 4. **Require explicit authorization** - Ensure every local image originates from a user-provided attachment or an explicitly approved path. - Require confirmation before accessing paths outside the host’s attachment directory. - Do not allow diary text or retrieved conversation content to introduce local file paths automatically. 5. **Minimize path disclosure** - Do not place absolute local paths or detailed exception messages in Notion fallback paragraphs. - Replace them with a generic message such as `Image upload failed`. - Keep detailed diagnostics local and redact home-directory and credential-related paths. 6. **Add security tests** - Verify rejection of files such as SSH keys, environment files, and arbitrary text documents. - Test path traversal, home-directory expansion, symbolic links, misleading image extensions, malformed images, and files outside approved roots. - Confirm that valid user attachments continue to upload successfully.