For security reasons some PHP functions like exec, shell_exec etc. are disabled by default on our shared hosting servers. This protects against attackers who exploit a security hole in your website and then execute a service or critical commands on your hosting. We understand that functions like exec() are required today by some big CMS systems like Typo3 for Imagemagick, Ghostscript and PHP scripts, so we offer the manual activation of exec.
If you want to activate exec() on your Linux hosting, please send us an email with the domain name concerned.