On a website I run I've recently noted in the apache error logs a number of url-encoded requests ala 

  GET /cgi-bin/script.cgi?c%3D1%3Bu%3D1%3B...

[download]
which causes the script to fail, whereas using the comparable query string 
  GET /cgi-bin/script.cgi?c=1;u=1;...

[download]
is successful. My website uses perl v5.8.0 and apache 2.0.46, but I tested this on my less dated home server using perl 5.18.2 and apache 2.4.7 with the same result.

The perl script uses 

  use CGI ;
  my $query = new CGI;
  $cparam = $query->param('c');
  $uparam = $query->param('u');

[download]
Should this be happening? I had assumed the CGI module would handle url-encoded input. Is there a way to treat this?

I should add that the url-encoded cases are very rare and may come from some kind of bot instead of a human user.

LATER - decided that the submitted query string is invalid and should not be expected to be processed by CGI since query string delimiters have been encoded, making parsing of parameter name and value impossible. Will now try to delete this post, but leaving this in case I can't figure that out

In reply to CGI of url-encoded query string by glendeni

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