CVE-2020-13671
Description
Drupal core does not properly sanitize certain filenames on uploaded files, which can lead to files being interpreted as the incorrect extension and served as the wrong MIME type or executed as PHP for certain hosting configurations. This issue affects: Drupal Drupal Core 9.0 versions prior to 9.0.8, 8.9 versions prior to 8.9.9, 8.8 versions prior to 8.8.11, and 7 versions prior to 7.74.
Summary dbcve.org
Drupal core fails to properly sanitize filenames on uploaded files, allowing attackers to craft filenames that cause the server to misinterpret file extensions and MIME types. In certain hosting configurations (particularly when PHP execution is enabled for uploaded files), this can lead to remote code execution by uploading files that get executed as PHP rather than served as static content.
Mitigation
Upgrade Drupal core to version 7.74, 8.8.11, 8.9.9, 9.0.8 or later. For hosting environments where immediate patching is not possible, disable PHP execution in uploaded file directories and ensure files are served with correct MIME types from outside the web root.