Limiting which formats are loaded with PIL images

Question

To reduce the number of possible attack vectors on a website, which would be the best way to limit formats, the Python Imaging Library can read a set of well-known good codecs (GIF, JPEG, PNG).

Thus, users could not send more exotic formats and use possible codec errors for buffer overflows, etc.

Preferably at runtime.

Answer 1

You can use python-magic to check the accepted mimety types before passing the file / buffer to PIL.