publish.ical.php in Jim Hu and Chad Little PHP iCalendar 2.21 and earlier does not require authentication for write access to the calendars directory, which…

publish.ical.php in Jim Hu and Chad Little PHP iCalendar 2.21 and earlier does not require authentication for write access to the calendars directory, which allows remote attackers to upload and execute arbitrary PHP scripts via a WebDAV PUT request with a filename containing a .php extension and a trailing null character.