security: validate upload filenames and archive paths

CHANGELOG.md

@@ -43,6 +43,8 @@ Follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) · versioned wi
   changing those fields causes the existing pair to be flagged stale.
 - **Character Table Pagination.** Productions now render 50 character cards/rows at a time with an explicit Show more
   control, keeping sorting and record lookups intact while reducing DOM and image work for large casts.
+- **Upload Filename Boundaries.** Audio, STT, route-sound and picture uploads now reject path-like or control-character
+  filenames before deriving extensions; voice ZIP imports also reject absolute, traversal and malformed archive paths.
 - **Security Regression Coverage.** Added a Python test gate for character metadata validation, private-download URL
   rejection and oversized JSON request rejection.
 - **Navigation Reliability.** Rehearser phase requests now survive the feature-module initialization boundary.

TODO.md

@@ -20,8 +20,8 @@ the first block before investing in architecture or polish.
 - [ ] **S — Stop API keys from reaching frontend JavaScript or logs.** Provider keys are now masked in settings
   responses and probes use server-side credentials; finish the external-client key handoff and audit remaining
   transient input/error paths.
-- [ ] **S — Validate uploaded filenames and paths.** Reject traversal, unsafe names and
-  writes outside the intended data directories.
+- [x] **S — Validate uploaded filenames and paths.** Upload endpoints reject traversal, path separators and control
+  characters before deriving extensions; ZIP imports reject absolute, traversal and malformed archive members.
 - [ ] **M — Add upload, request-size, temporary-file and concurrent-job limits.** Apply
   endpoint-specific caps and clean up intermediates on failure.
 - [x] **M — Add automatic backups before bulk deletes, voice moves and recasts.** Make

core/validation.py

@@ -52,6 +52,19 @@ def _copy_limited(src, dest, limit: int) -> int:
     return total
 
 
+def _validated_upload_suffix(filename: str | None, *, default: str, allowed: set[str]) -> str:
+    """Validate a browser upload name and return its normalized suffix."""
+    name = str(filename or default)
+    if not name or len(name) > 255 or any(ord(char) < 32 or ord(char) == 127 for char in name):
+        raise HTTPException(400, "Invalid upload filename")
+    if "/" in name or "\\" in name or name in {".", ".."}:
+        raise HTTPException(400, "Upload filename must not contain a path")
+    suffix = Path(name).suffix.lower() or default
+    if suffix not in allowed:
+        raise HTTPException(400, "Unsupported file type")
+    return suffix
+
+
 def _safe_child_path(root: Path, candidate: Path) -> Path:
     root_resolved = root.resolve()
     candidate_resolved = candidate.resolve()

routes/conversation.py

@@ -3961,10 +3961,14 @@ async def voices_import(file: UploadFile = File(...)):
             for info in zf.infolist():
                 if info.is_dir():
                     continue
-                parts = Path(info.filename).parts
-                if any(p in ("..", "") for p in parts) or Path(info.filename).name == "settings.json":
+                archive_name = str(info.filename or "")
+                parts = tuple(archive_name.replace("\\", "/").split("/"))
+                if (not archive_name or archive_name.startswith(("/", "\\"))
+                        or any(p in ("..", "") for p in parts)
+                        or any(ord(char) < 32 or ord(char) == 127 for char in archive_name)
+                        or Path(parts[-1]).name == "settings.json"):
                     continue
-                if Path(info.filename).suffix.lower() not in _IMPORT_ALLOWED_SUFFIXES:
+                if Path(parts[-1]).suffix.lower() not in _IMPORT_ALLOWED_SUFFIXES:
                     continue
                 rel = parts[1:] if len(parts) > 1 else parts
                 dest = scan_dir / Path(*rel)

routes/library.py

@@ -14,7 +14,7 @@ from fastapi.responses import FileResponse, Response
 from core.config import _load_settings
 from core.constants import _VOICES_DIR_DEFAULT, _OUTPUT_DIR_DEFAULT, _VOICE_TARGET_DBFS, _VOICE_PEAK_DBFS, _BENCHMARK_SENTENCES, _MAX_TTS_OUTPUT_SECONDS, _MAX_UPLOAD_BYTES, _MAX_PICTURE_BYTES, _MAX_SOUND_BYTES, _ALLOW_PRIVATE_DOWNLOADS
 from core.registry import _registry_put, _registry_get, TEMP_DIR
-from core.validation import _copy_limited, _safe_child_path, _validate_http_url
+from core.validation import _copy_limited, _safe_child_path, _validate_http_url, _validated_upload_suffix
 from core.audio import (
     _to_wav_24k, _to_wav_16k, _trim, _duration, _export_normalized_wav,
     _loudness_info, _auto_trim_bounds, _normalize_segment,
@@ -147,9 +147,7 @@ async def save_book_profile(request: Request):
 
 @router.post("/api/upload")
 async def upload(file: UploadFile = File(...)):
-    suffix = Path(file.filename or "audio").suffix.lower() or ".bin"
-    if suffix not in _UPLOAD_EXTS:
-        raise HTTPException(400, "Unsupported audio/video file type")
+    suffix = _validated_upload_suffix(file.filename, default=".bin", allowed=_UPLOAD_EXTS)
     dest = TEMP_DIR / f"{uuid.uuid4().hex}{suffix}"
     try:
         with dest.open("wb") as f:
@@ -227,9 +225,7 @@ async def route_sound_file(sound_path: str):
 async def upload_route_sound(file: UploadFile = File(...), name: str = Form("")):
     from pydub import AudioSegment
 
-    suffix = Path(file.filename or "sound").suffix.lower() or ".bin"
-    if suffix not in _AUDIO_EXTS:
-        raise HTTPException(400, "Unsupported sound file type")
+    suffix = _validated_upload_suffix(file.filename, default=".bin", allowed=_AUDIO_EXTS)
     raw_name = Path(name or file.filename or "sound").stem.strip()
     safe_name = re.sub(r"[^A-Za-z0-9_\-.]+", "_", raw_name).strip("._-")[:80] or f"sound_{uuid.uuid4().hex[:8]}"
     settings = _load_settings()
@@ -945,9 +941,7 @@ async def upload_picture(voice_id: str = Form(...), file: UploadFile = File(...)
     if wav is None:
         raise HTTPException(404, f"Voice '{voice_id}' not found")
 
-    orig_suffix = Path(file.filename or "photo.jpg").suffix.lower()
-    if orig_suffix not in _PICTURE_EXTS:
-        orig_suffix = ".jpg"
+    orig_suffix = _validated_upload_suffix(file.filename, default=".jpg", allowed=_PICTURE_EXTS)
 
     _backup_existing_picture(wav)
     for ext in _PICTURE_EXTS:

routes/stt.py

@@ -19,7 +19,7 @@ from core.constants import (
     _MAX_UPLOAD_BYTES, _STT_REQUEST_TIMEOUT,
 )
 from core.registry import _registry_get, TEMP_DIR
-from core.validation import _validate_http_url, _copy_limited
+from core.validation import _validate_http_url, _copy_limited, _validated_upload_suffix
 from core.audio import _to_wav_16k
 from core.voice import _AUDIO_EXTS, _UPLOAD_EXTS
 
@@ -506,9 +506,7 @@ async def transcribe_bytes(
     backend: str = Form("configured"),
 ):
     """Accept raw audio upload and return transcription directly (used by hotkey daemon)."""
-    suffix = Path(file.filename or "audio.wav").suffix.lower() or ".wav"
-    if suffix not in _AUDIO_EXTS:
-        raise HTTPException(400, "Unsupported audio type")
+    suffix = _validated_upload_suffix(file.filename, default=".wav", allowed=_AUDIO_EXTS)
     tmp = TEMP_DIR / f"{uuid.uuid4().hex}_daemon{suffix}"
     wav_tmp = tmp
     try:
@@ -554,9 +552,7 @@ async def stt_benchmark(
         else:
             if audio is None:
                 raise HTTPException(400, "Audio file or voice library sample is required")
-            suffix = Path(audio.filename or "audio.wav").suffix.lower() or ".wav"
-            if suffix not in (_AUDIO_EXTS | _UPLOAD_EXTS):
-                raise HTTPException(400, "Unsupported audio type")
+            suffix = _validated_upload_suffix(audio.filename, default=".wav", allowed=(_AUDIO_EXTS | _UPLOAD_EXTS))
             tmp = TEMP_DIR / f"{uuid.uuid4().hex}_stt_bench{suffix}"
             wav_tmp = tmp
             with tmp.open("wb") as f:

tests/test_security.py

@@ -10,7 +10,7 @@ os.environ.setdefault("CONFIG_DIR", tempfile.mkdtemp(prefix="ttvc-test-config-")
 
 from fastapi import HTTPException
 
-from core.validation import _validate_character_record, _validate_http_url
+from core.validation import _validate_character_record, _validate_http_url, _validated_upload_suffix
 from core.config import _load_settings, _save_settings
 from server import RequestSizeLimitMiddleware
 
@@ -32,6 +32,12 @@ class SecurityValidationTests(unittest.TestCase):
         with self.assertRaises(HTTPException):
             _validate_http_url("http://127.0.0.1:8188/image", allow_private=False)
 
+    def test_upload_filename_rejects_paths_and_control_characters(self):
+        for filename in ("../voice.wav", r"folder\\voice.wav", "voice\x00.wav"):
+            with self.assertRaises(HTTPException):
+                _validated_upload_suffix(filename, default=".wav", allowed={".wav"})
+        self.assertEqual(_validated_upload_suffix("VOICE.WAV", default=".wav", allowed={".wav"}), ".wav")
+
     def test_request_size_middleware_rejects_oversized_json(self):
         sent = []