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.

Directory traversal vulnerability in Jim Hu and Chad Little PHP iCalendar 2.21 and earlier allows remote attackers to include and execute arbitrary local files via directory traversal sequences and a NUL (%00) character in the phpicalendar[cookie_language] and phpicalendar[cookie_style] cookies, as demonstrated by injecting PHP sequences into an Apache access_log file, which is then included by day.php.

PHP file inclusion vulnerability in index.php in PHP iCalendar 2.0a2 through 2.0.1 allows remote attackers to execute arbitrary PHP code and include arbitrary local files via the phpicalendar cookie. NOTE: this is not a cross-site scripting (XSS) issue as claimed by the original researcher.