If you read the e-smith.org front page, like all of it going down, you'll be aware of any vulnerabilities that are known in a default installation. If you've installed the 5.1.2 blade update one, or the php fix, you're ok for the php file upload vulnerability.
Unknown vulnerabilities are NOT listed, for obvious reasons....
Once you start sticking things onto your server, things change and you'll have to monitor other places for security warnings, if they eventuate.
The only people I've seen get owned in these forums have put programs like PHPNuke on their server, which have known exploits....