Blocking Inappropriate Content on Contact Form

Milti has asked for the wisdom of the Perl Monks concerning the following question:

I have a Perl program on my server to prevent certain words being used when my contact form is submitted. For the most part it is working but a single "spammer" has somehow found a way around it. Here is the code.

$String=param('Message');

if ($String =~ /porn/) {

print "<p><font size=+4\">Goodbye</font></p>";
exit;}

if ($String =~ /sex/) {
print "<p><font size=+4\">Goodbye</font></p>";
exit;}

if ($String =~ /girls/ ) {
print "<p><font size=+4\">Goodbye</font></p>";
exit;}
[download]

The rest of the program checks for "Not a Robot", Enter Anti Spam number, etc and then forwards the message to my email service. When I get an inappropriate message I can copy it and paste in my contact form and the message will not be sent, i.e. I get a "Goodbye" return. How can this be? How is the spammer getting by my safeguards?

Any and all help will be appreciated. Tks!

Comment on Blocking Inappropriate Content on Contact Form Download Code

Replies are listed 'Best First'.
Re: Blocking Inappropriate Content on Contact Form by afoken (Chancellor) on Jul 19, 2022 at 16:03 UTC
if ($String =~ /sex/) { What's wrong with "Greetings from Essex"? The rest of the program checks for "Not a Robot", Enter Anti Spam number, etc and then forwards the message to my email service. [...] How can this be? How is the spammer getting by my safeguards? By using the email service directly, bypassing those trivial checks? Add some logging, especially log `$String` (plus date plus remote IP). If you still get spam, but find no traces in the log, that's what happened. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply] [d/l]
Re^2: Blocking Inappropriate Content on Contact Form by AnomalousMonk (Archbishop) on Jul 19, 2022 at 18:14 UTC
What's wrong with "Greetings from Essex"? ... or, indeed, from Scunthorpe? Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re^3: Blocking Inappropriate Content on Contact Form by bliako (Monsignor) on Jul 19, 2022 at 19:58 UTC
my lols woke up the poor whakers!	[reply]
Re: Blocking Inappropriate Content on Contact Form by haukex (Archbishop) on Jul 19, 2022 at 15:10 UTC
How is the spammer getting by my safeguards? You'd need to post the actual, raw data you're receiving in order for us to be able to tell, along with code (SSCCE). Perhaps they're using some Unicode characters (that don't survive your copy&paste)? See all the advice you got in your last thread Bad Language In Contact Messages.	[reply]
Re: Blocking Inappropriate Content on Contact Form by bliako (Monsignor) on Jul 19, 2022 at 19:49 UTC
Perhaps they think all these inappropriate content deserve to be Capitalised? (edit: adding a second version: perhaps these inappropriate content is Capitalised in their books?) `$String =~ /girls/i` bw, bliako	[reply] [d/l]


Do you know where your variables are?
	PerlMonks