libexif through 0.6.25 has a flaw in decoding MakerNotes. If the exif_mnote_data_get_value function gets passed in a 0 size, the passed in-buffer would be overwritten due to an integer underflow.
https://github.com/libexif/libexif/issues/247
https://github.com/libexif/libexif/commit/7df372e9d31d7c993a22b913c813a5f7ec4f3692