First of all, the same thing thanos1983 asked: what version of Perl will the script be running on? Net::OpenSSH, which you've commented out, works down to Perl v5.8 and would be the module I'd recommend, even if it may be tricky to install on your legacy system I'd still suggest you give it a try. It looks like it's a pure Perl module.
The one thing I see is that in the command you construct, if $cmd->{command} contains any characters that would influence the shell quoting (e.g. '), you'll have trouble. If you can, I'd recommend IPC::System::Simple's replacement for qx, capturex. Otherwise, as I wrote about at length here, you might also use piped opens that avoid the shell (also available starting Perl v5.8). If you're on a Perl <5.8, you may have to live with backticks and the potential problems, or you could maybe have a look at String::ShellQuote to alleviate some of those worries.
