I don't use the affected version of xoopsgallery, but here is a hack that catches the POC. Add these lines just before the final "}" in TRUST PATH modules/protector/include/postcheck_functions.php
// xoopsgallery protection hack
if( isset($_GET['GALLERY_BASEDIR'])) {
if((substr($_GET['GALLERY_BASEDIR'],0,5)=='http:') ||
(substr($_GET['GALLERY_BASEDIR'],0,4)=='ftp:')) {
die("xoopsgallery remote file include attack");
}
}
Since xoopsgallery.org is offline, I have no way to check on the status or possibility of a proper fix, but maybe this will help you stay up long enough to find and implement a better solution.
Good luck,
-Richard