A file disclosure and inclusion vulnerability exists in web/views/file.php in ZoneMinder 1.x through v1.30.0 because of unfiltered user-input being passed to readfile(), which allows an authenticated attacker to read local system files (e.g., /etc/passwd) in the context of the web server user (www-data). The attack vector is a .. (dot dot) in the path parameter within a zm/index.php?view=file&path= request.
