A possible security bug fix

[Douglas]

Not too long ago there was a news item pointing out the potential 
for working mischief by running programs with file descriptors 0, 
1 or 2 closed - for example, the program could open a file which 
would end up having file descriptor 2, and then write a message 
to standard error, modifying the file.

Would there be any problems with requiring file descriptors 0, 1 and 2
to be open during an exec?  (making an exception for pid 1, so the
initial exec of /etc/init works).