The Iptanus File Upload WordPress plugin before 5.1.7 does not implement proper file handling...

The Iptanus File Upload WordPress plugin before 5.1.7 does not implement proper file handling when the duplicatepolicy setting is configured to "maintain both." Due to a Time-of-Check to Time-of-Use (TOCTOU) race condition between the file existence check and the actual file write operation, an authenticated attacker can overwrite files uploaded by other users.