Regex, Taint, Review

[K.L. Hayes]

Hello All,

I have a script to process an inquiry form.(go figure ;)

Anyway, if someone could take a quick look and see if I'm missing
anything obvious or see anything that would allow a breach in
security, I would appreciate it.

Particularly my regex filters may need a third eye to catch something
because they still aggravate my brain tumor to figure out sometimes.

Also, I'd like to turn on taint checking but I believe that my
$ENV{'HTTP_REFERER'} & $ENV{REMOTE_ADDR} are the cause of errors when
I do. If someone could show me how to fix this, I'll name my third
born after you.

Also, before anybody gets their panties in a bundle, I've read all the
banter on this list about validating email addresses & how it can't be
done 100% of the time, the mods to look at & such. I'm just shooting
for a high 80% success. I got fred&[EMAIL PROTECTED] taken care of &
the rest can read my error page telling them to just send me an e-mail
with the info... ;)

Code is below, thanks a bunch!

<CODE>
#!/usr/bin/perl -w

use strict;
use CGI qw(:standard);
$CGI::DISABLE_UPLOADS = 1;
$CGI::POST_MAX        = 512 * 1024;

my ($ENV,$sendmail,$time,$name,$email,$subject,$comments,
    $bad_name,$bad_email,$bad_subject,$bad_comments);

$sendmail = '/usr/sbin/sendmail';
$time  = localtime(time);

$bad_name = param('name');
if ( $bad_name =~ /^([a-zA-Z\s_]+)$/ ) {
        $name = $1; }
        else {
        error();
        exit; }

$bad_email = param('email');
if( $bad_email =~ m/\w\S+\@\w\S+\./) {          
        $bad_email =~ /([\w+\-\&\._]+\@[\w+\.\-_]+)/;
        $email = $1; }
        else {
        error();
        exit; }

# A one-word drop-down menu selection for this one. If they try to
# send anything else here... they can bite me ;)
$bad_subject = param('subject');
if ( $bad_subject =~ /^([a-zA-Z]+)$/ ) {
        $subject = $1; }
        else {
        error();
        exit; }

$bad_comments = param('comments');
if ( $bad_comments =~ /^([a-zA-Z\d\s\-\.\?!,_]+)$/ ) {
        $comments = $1; }
        else {
        error();
        exit; }

if (($ENV{'HTTP_REFERER'} eq "http://www.my-domain.com/contact/index.html";) ||
    ($ENV{'HTTP_REFERER'} eq "http://my-domain.com/contact/index.html";) ||
    ($ENV{'HTTP_REFERER'} eq "http://www.my-domain.com/contact/";) ||
    ($ENV{'HTTP_REFERER'} eq "http://my-domain.com/contact/";))
{
# DO NADA - JUST CONTINUE ON
}
else {
invalid();
exit; }

if(param()) {
open (MAIL, "| $sendmail -t -oi") || die "Can't open $sendmail : $!\n";
print MAIL "To: webmaster\@my-domain.com\n";
print MAIL "From: webmaster\@my-domain.com\n"; 
print MAIL "Subject: $subject\n\n";
print MAIL "On $time\n";
print MAIL "This information was received:\n\n";

## Personal Information ##

print MAIL "Inquiry Information:\n";
print MAIL "$ENV{REMOTE_ADDR}\n";
    if($name) {
print MAIL "Name: $name\n"; }
    else { error(); }
    if($email) {
print MAIL "E-Mail: $email\n"; }
    else { error(); }
    if($subject) {
print MAIL "Subject: $subject\n"; }
    else { error(); }
    if($comments) {
print MAIL "Comments: $comments\n"; }
    else { error(); }
close(MAIL);

print "Location: http://www.my-domain.com/thankyou.html\n\n";;
exit; }

print "Location: http://www.my-domain.com/contact/index.html\n\n";;

sub error {
print "Location: http://www.my-domain.com/contact/error.html\n\n";;
}
sub invalid {
print "Location: http://www.my-domain.com/contact/invalid.html\n\n";;
}
</CODE>

-- 
Best regards,
K.L. Hayes
mailto:[EMAIL PROTECTED]

+=====================================================+
+ "Only two things are infinite, the universe and     +
+ human stupidity, and I'm not sure about the former."+
+                                 -- Albert Einstien  +
+=====================================================+



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