How To fix the Drush error "exec() has been disabled for security reasons bootstrap.inc"
I occasionally have to deal with shared hosting. Which I'll admit, I'm not real happy about as I generally have to install a bunch of my default tools, most of which then have to be 'fixed' to work on [insert cheap hosting firm's name]'s concept of security.
As I just did this (again), here is the 'patch' for drush to make it 'play nice.'
Copy php.ini to a drush usable location and edit for your problems.