U&M Software Event Lister (aka JustListIt) 1.0 does not require administrative authentication for all scripts in the admin/ directory, which allows remote attackers to have an unspecified impact via a direct request to (1) start.php, (2) aktivitet.php, (3) prop_aktivitet.php, (4) kategorier.php, (5) konfig.php, (6) security.php, (7) manual.php, and possibly (8) index.php.