Re: URGENT SECURITY ADVISORY FOR SSH SECURE SHELL 3.0.0

From: Nate Eldredge (neldredgeat_private)
Date: Sun Jul 22 2001 - 06:14:25 PDT

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    On 21 Jul 2001, Dale Southard wrote:
    
    > Sshd should probably be constraining its match to the length of the
    > crypt() output rather than the length of the password file entry.  [I
    > say ``probably'' here because some systems (AIX) seem to produce null
    > password file hashes when `passwd` is given a null password.  If that
    > behavior is due to the underlying crypt() function, then the
    > ``probably'' suggestion I just made yields remote root on those
    > systems.]
    
    What's wrong with just using `strcmp' (i.e. no constraint at all)?  After
    all, what you want to know is just whether the two strings are identical,
    period.  And unless crypt() and /etc/shadow are both broken, it will stop 
    at the right place.  I realize it goes against the reflexive "only strn*
    functions are safe" idea, but that shouldn't substitute for thinking...
    
    -- 
    
    Nate Eldredge
    neldredgeat_private
    



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