Re: Fix for ssh-1.2.27 symlink/bind problem

From: Markus Friedl (markus.friedlat_private-ERLANGEN.DE)
Date: Mon Oct 25 1999 - 15:19:02 PDT

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    On Wed, Oct 06, 1999 at 11:11:12AM -0400, Wietse Venema wrote:
    > This is the second SSH vulnerability involving bind() (the other
    > one involve port forwarding). They really ought to learn to perform
    > operations with the right privilege level.
    >
    > With a little tooling (such as set_eugid()) it is quite easy.
    
    please note, that ssh dropped support for uid-swapping beginning
    with version 1.2.13:
    in order to avoid leakage of the private hostkey (e.g. in core-dumps)
    when running suid-root, ssh now forks into 2 processes:
    	(1) the main process is running setuid root and controls:
    	(2) the 'userfile' process, which runs with the id of the user and
    	accesses his files (e.g. over NFS)
    
    i think it is the wrong decision to make 'privileged' the standard
    and 'non-privileged' the special case.
    
    please note also, that the two free versions of ssh, ossh by
    Bjoern Groenvall <bgat_private> and OpenSSH from the OpenBSD-project,
    do _not_ exhibit this behaviour, since they are derived from ssh-1.2.12,
    the last version of the original ssh, free for commercial use.
    



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