Security and $PATH

[John Nelson]

I really  don't  understand  what all the  hoopla  is about! An
unsophisticated   user  who  never  cd's  to   someone   else's
directory  tree wishes to have the current  directory  searched
FIRST for  commands  (so that his commands  will  override  the
system  command  names.)  Anyone who is somewhat  sophisticated
will know  about  existing  command  names, and will  generally
avoid  naming  his own  programs  with a  conflicting  name! To
avoid  someone  else  renaming a standard  command  (or even to
protect himself from accidently  doing something as disasterous
as the "du" delete user  syndrome)  all he has to do is put the
"."  directory  LAST in his  path! No one  should  ever have to
type a  command  as  ./command,  even  as a  security  measure,
unless  someone  has  stupidly  named a  program  the same as a
standard program! 

As  for  programs  with  standard  names  that  create  set-uid
programs, if your current  directory  belongs to someone  else,
then the burden of being  careful us up to YOU! If you  execute
programs  on  someone  else's   directory,  you  get  what  you
deserve!