312-92 Question #41: Real Exam Question with Answer & Explanation

William, a software developer just starting his career, was asked to create a website in PHP that would allow visitors to enter a month and a year for their birth date. The PHP code he creates has to validate the input after it is entered. If William uses the following code, what could a malicious user input to the year value to actually delete the whole website? $month = $_GET['month']; $year = $_GET['year']; exec("cal $month $year", $result); print "<PRE>"; foreach($result as $r) { EC-Council 312-92 Exam print "$r<BR>"; } print "</PRE>";