============
something.lib
============
sub safer {
    my $hash = shift;
    my %safer;
    while (my ($k, $v) = each %$hash) {
        s/\\//g         for $k, $v;
        s/0x00//g       for $k, $v;
        s/0x08//g       for $k, $v;
        s/0x09//g       for $k, $v;
        s/0x0a/\n/g     for $k, $v;
        s/0x0d/\r/g     for $k, $v;
        s/"/\\"/g       for $k, $v;
        s/%/\\%/g       for $k, $v;
        s/'/\\'/g       for $k, $v;
        s/_/\_/g        for $k, $v;

        $safer{$k} = $v;
    }
    return %safer;
}

================
something.cgi...
================
use warnings;
use strict;
use CGI;
use CGI::Carp;

print "Content-type: text/html\n\n";

# marker
my $cgi = CGI->new();

$cgi->param;
my %params;

for my $name ($cgi->param) {
    my @values = $cgi->param($name);
    $params{$name} = @values > 1 ? \@values : $values[0];
}

%params=safer(\%params);
# marker

for my $param (keys %params) {
    print "$param: $params{$param}<br>"
}