[core,utils] Support unpublicised `--no-check-extensions`

youtube_dl/__init__.py

@@ -21,6 +21,7 @@ from .compat import (
     workaround_optparse_bug9161,
 )
 from .utils import (
+    _UnsafeExtensionError,
     DateRange,
     decodeOption,
     DEFAULT_OUTTMPL,
@@ -173,6 +174,9 @@ def _real_main(argv=None):
     if opts.ap_mso and opts.ap_mso not in MSO_INFO:
         parser.error('Unsupported TV Provider, use --ap-list-mso to get a list of supported TV Providers')
 
+    if opts.no_check_extensions:
+        _UnsafeExtensionError.lenient = True
+
     def parse_retries(retries):
         if retries in ('inf', 'infinite'):
             parsed_retries = float('inf')

youtube_dl/options.py

@@ -533,6 +533,10 @@ def parseOpts(overrideArguments=None):
         '--no-check-certificate',
         action='store_true', dest='no_check_certificate', default=False,
         help='Suppress HTTPS certificate validation')
+    workarounds.add_option(
+        '--no-check-extensions',
+        action='store_true', dest='no_check_extensions', default=False,
+        help='Suppress file extension validation')
     workarounds.add_option(
         '--prefer-insecure',
         '--prefer-unsecure', action='store_true', dest='prefer_insecure',

youtube_dl/utils.py

@@ -6587,7 +6587,6 @@ KNOWN_EXTENSIONS = (
 class _UnsafeExtensionError(Exception):
     """
     Mitigation exception for unwanted file overwrite/path traversal
-    This should be caught in YoutubeDL.py with a warning
 
     Ref: https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-79w7-vh3h-8g4j
     """
@@ -6666,6 +6665,9 @@ class _UnsafeExtensionError(Exception):
         super(_UnsafeExtensionError, self).__init__('unsafe file extension: {0!r}'.format(extension))
         self.extension = extension
 
+    # support --no-check-extensions
+    lenient = False
+
     @classmethod
     def sanitize_extension(cls, extension, **kwargs):
         # ... /, *, prepend=False
@@ -6678,7 +6680,7 @@ class _UnsafeExtensionError(Exception):
             last = extension.rpartition('.')[-1]
             if last == 'bin':
                 extension = last = 'unknown_video'
-            if last.lower() not in cls._ALLOWED_EXTENSIONS:
+            if not (cls.lenient or last.lower() in cls._ALLOWED_EXTENSIONS):
                 raise cls(extension)
 
         return extension