I have run the following code on Win32 using ActiveState perl 5.6.

#!/usr/local/bin/perl -Tw
       use CGI ':standard';
       $file = param('file');
       $comment = param('comment');
       unless ($file) { $file = 'xcanalys.txt'; }
       unless ($comment) { $comment = 'No comment'; }
       open (OUTPUT, ">>./" . $file) or die "$!";
       print OUTPUT $comment . "\n";
       close OUTPUT;
       print header, start_html;
       print "<P>Thanks!</P>\n";       
       print end_html;
1;
[download]

Here is the command line:

perl -T tainttest.pl
(offline mode: enter name=value pairs on standard input)
^Z
[download]

Without untainting the information coming out from param(), this short script appends to the file! Isn't this supposed to fail?

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