WordPress before 4.9.9 and 5.x before 5.0.1 allows remote code execution
because an _wp_attached_file Post Meta entry can be changed to an arbitrary
string, such as one ending with a .jpg?file.php substring. An attacker with
author privileges can execute arbitrary code by uploading a crafted image
containing PHP code in the Exif metadata. Exploitation can leverage
CVE-2019-8943.