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).