Security of system executables e.g. in /usr/bin/

[jack01]

Hi,

I would like to know what the implcations would be of setting chmod 700 on all files within /usr/bin/ and perhaps /usr/local/bin/ that are owned by root.root

If exec() is enabled in PHP some bad things are possible with access to system executables, even with suphp it seems.

Also, is there any way of limiting the executables on the server that can be run by the php exec() system() etc.?

Many thanks in advance for any useful pointers.