--- formmail.cgi.orig	Wed May 10 23:34:09 2000
+++ formmail.cgi	Thu May 11 00:14:22 2000
@@ -34,6 +34,13 @@
 
 @referers = ('worldwidemart.com','206.31.72.203');
 
+# @validrecipients limits what email addresses can receive form submissions;
+# this should be an array of regular expressions. Note that the recipient
+# value should contain only one Internet email address; use an alias or
+# hack the script more if you need/want multiple recipients for one form
+
+@validrecipients = ( '^[a-z]{1,}\@goodguys\.example\.com$' );
+
 # Done                                                                       #
 ##############################################################################
 
@@ -175,10 +182,16 @@
     # names or environment variables.                                        #
     $Config{'required'} =~ s/(\s+|\n)?,(\s+|\n)?/,/g;
     $Config{'required'} =~ s/(\s+)?\n+(\s+)?//g;
+    # required fields should have alphanumeric names; this
+    # helps combat cross-site scripting probs in &error()
+    $Config{'required'} =~ s/[^a-zA-Z0-9\_]//gs;
     $Config{'env_report'} =~ s/(\s+|\n)?,(\s+|\n)?/,/g;
     $Config{'env_report'} =~ s/(\s+)?\n+(\s+)?//g;
     $Config{'print_config'} =~ s/(\s+|\n)?,(\s+|\n)?/,/g;
     $Config{'print_config'} =~ s/(\s+)?\n+(\s+)?//g;
+    # missing_fields_redirect should not be used to add arbitrary server
+    # headers, etc.; scrub its contents
+    $Config{'missing_fields_redirect'} =~ s/[^a-zA-Z0-9\_\:\/\-]//gs;
 
     # Split the configuration variables into individual field names.         #
     @Required = split(/,/,$Config{'required'});
@@ -194,6 +207,18 @@
     if (!$Config{'recipient'}) {
         if (!defined(%Form)) { &error('bad_referer') }
         else                 { &error('no_recipient') }
+    } else {
+	# have recipient; is it OK?
+	$recipientOK = 0;
+	foreach $possibleRecipient ( @validrecipients ) {
+		if ( $Config{'recipient'} =~ /$possibleRecipient/i ) {
+			$recipientOK = 1;
+			last;
+		}
+	}
+	if ( $recipientOK != 1 ) {
+		&error('no_recipient');
+	}
     }
 
     # For each require field defined in the form:                            #
@@ -570,10 +595,10 @@
  <body bgcolor=#FFFFFF text=#000000>
   <center>
    <table border=0 width=600 bgcolor=#9C9C9C>
-    <tr><th><font size=+2>Error: No Recipient</font></th></tr>
+    <tr><th><font size=+2>Error: No Valid Recipient</font></th></tr>
    </table>
    <table border=0 width=600 bgcolor=#CFCFCF>
-    <tr><td>No Recipient was specified in the data sent to FormMail.  Please
+    <tr><td>No Valid Recipient was specified in the data sent to FormMail.  Please
      make sure you have filled in the 'recipient' form field with an e-mail
      address.  More information on filling in recipient form fields can be
      found in the README file.<hr size=1>