Re: Glibc Local Root Exploit

[Philip Rowlands <phr () DOC IC AC UK>]

Pedro Margate wrote:
> The implementations of ssh that I'm familiar with (ssh and OpenSSH)
> install the ssh binary as suid root by default.  This can be disabled
> during configuration or after the fact with chmod.  I believe that would
> prevent this exploit from operating.  I've turned off the suid bit on
> every ssh installation I've performed and it seems to work the same.  I'm
> not sure what reason ssh has to be suid root, nobody I've asked has any
> idea.

Ssh was designed as a drop-in replacement for rsh/rlogin, by name if
necessary. Therefore, it has to be able to copy rsh's behaviour of
originating connections from a privileged port (yes, that's a lame
"security" feature"). If you don't need this, remove the SUID bit. I
would much prefer distributions to ship an unprivileged ssh client, with
guidance on how/why to enable it if necessary.


Cheers,

Phil