:On Mon, Jul 26, 1999, Nate Williams wrote:
:> > > LD_LIBRARY_PATH, LD_PRELOAD and LD_DEBUG are ignored for setuid 
executables
:> > > in FreeBSD.
:> > 
:> > But the point being made is that they are not ignored for executables
:> > which have no read access.  And from there, read access can be gained,
:> > because at that point, you have code running in the process's address
:> > space.
:> 
:> That's right.  In other words, there really is no way of protecting
:> executable files from being read if someone is motivated enough.
:> 
:> And, in an open-source OS like FreeBSD, it's not a viable solution in
:> any case....
:
:   The only option, as I've mentined previously in this thread,
:that I can think of, would be to have an option when building
:various linker code to disable searching in $LD_LIBRARY_PATH if
:the library being looked for is in the standard library paths.
:
:-- 
:|Chris Costello <ch...@calldei.com>

    LD_LIBRARY_PATH was a huge security hole when it was first introduced
    and you know what?  It STILL IS!

    We are opening up a can of worms here.  It's one of those things where
    we either have to make the decision to try to protect the binary that
    the owner decided to make execute-only, or to give up.

        * LD_LIBRARY_PATH?
        * core dumps for execute-only binaries?
        * ktrace for execute-only binaries?

    If I were to put my foot down I would say off with their heads!  i.e.
    disallow all three if the non-root-run binary is execute-only.

                                        -Matt
                                        Matthew Dillon 
                                        <dil...@backplane.com>



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