Yes, you have an insecure dependency in system while running with the -T switch. :p
You're running your script in taintperl mode, and calling an external program (with sudo, no less) with data based on information passed in from the user (which could be tainted). If you're really sure that output is valid and doesn't pose risk, you need to untaint it: see the official documentation about laundering tainted data.
You need to be really careful when running external programs or performing system operations from a CGI -- for example, consider what might happen if you enter `rm -rf /`
as user input. There's lots of information at perldoc perlsec to get you started, but several books have been written about writing secure code as well.