Re: SSH deja vu

From: Michal Zalewski (lcamtufat_private)
Date: Tue Oct 23 2001 - 13:14:15 PDT

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    On Tue, 23 Oct 2001, Max Parke wrote:
    
    > When the vulnerabilities in ssh-1.xx were publicised, we upgraded to
    > ssh-2.xx on our machines.  The process for ssh version 2.xx does NOT
    > erase sshd1 from /usr/local/sbin, and if an incoming client is still
    > running the old ssh version 1, sshd2 will hand off control to
    > /usr/local/sbin/sshd1 (of course, this can be disabled).
    
    We mentioned this possibility in our original advisory, available at
    http://razor.bindview.com/publish/advisories/adv_ssh1crc.html, but it is
    good to mention it again today, when we observe massive exploitation of
    this vulnerability since private, multi-platform brute-force exploit
    authored by TESO security team leaked to the "underground" (not blaming
    TESO in particular: seeing several other exploits leaking this way in past
    few months - e.g. in.telnetd remote root - makes you wonder what's the
    real good of zero-disclosure policy and general ability of human beings to
    keep things available to "responsible parties" only). So far, people
    didn't see the threat (no exploits publicly available), and many didn't
    upgrade their daemons. Now, it is the time.
    
    If you do not use SSHv1, it is important to disable this feature, as
    SSH.com SSHv1 implementation is no longer actively maintained. If you have
    to stick to this protocol (which seems to be more vulnerable to certain
    cryptographic attacks than SSHv2), you should upgrade to 1.2.32, or switch
    to OpenSSH implementation - they implement SSHv1 in main daemon code and
    still seem to maintain it.
    
    -- 
    _____________________________________________________
    Michal Zalewski [lcamtufat_private] [security]
    [http://lcamtuf.coredump.cx] <=-=> bash$ :(){ :|:&};:
    =-=> Did you know that clones never use mirrors? <=-=
              http://lcamtuf.coredump.cx/photo/
    



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