run CGI in taint mode

bin/access-check-manager.cgi.in

-#!/usr/bin/perl
+#!/usr/bin/perl -T
 
 use strict;
 use warnings;

lib/AccountManager/App.pm

@@ -483,6 +483,7 @@ sub req_complete_challenge {
     );
 
     eval {
+        local $ENV{PATH} = '/bin:/sbin:/usr/bin:/usr/sbin';
         Email::Sender::Simple->send($message);
     };
     $self->abort(