In Hoteldruid before 2.3.1, a division by zero was discovered in $num_tabelle in tab_tariffe.php (aka the numtariffa1 parameter) due to the mishandling of non-numeric values, as demonstrated by the /tab_tariffe.php?anno=[YEAR]&numtariffa1=1a URI. It could allow an administrator to conduct remote denial of service (disrupting certain business functions of the product).