Defeating (or at least confusing) neped.c

From: Seth McGann (smmat_private)
Date: Fri Sep 18 1998 - 09:03:18 PDT

  • Next message: Seth McGann: "Incorrect Linux ARP behavior"

    <snip>
    /* -----------------------------------------
    Network Promiscuous Ethernet Detector.
    Linux 2.0.x / 2.1.x, libc5 & GlibC
    -----------------------------------------
    (c) 1998 savageat_private
    -----------------------------------------
    Scan your subnet, and detect promiscuous
    linuxes. It really works, not a joke.
    -----------------------------------------
    [ http://www.rootshell.com/ ]
    <snip>
    
    This nifty program was released on rootshell a few days ago.  I'm suprised
    it hasn't got more play on bugtraq yet.  Using the ARP protocol, it is
    apparently possible to tell which machines on a subnet are sniffing.
    Without going into the details of how exactly this detector works (mainly
    because I'm not quite sure myself)  it is possible to defeat the detector
    by having your machine be shown as a false negative.
    
    <Hax0r> # /sbin/ifconfig eth0 -arp
    <Hax0r> # ./evilsniffer -i eth0
    
    Now the interface will not respond to ARP queries, thus no detection.  Not
    responding to ARP requests is suspicious but the fact remains that you
    can't be sure whether or not someone is sniffing.  Additionally, this
    program apparently will not detect sniffers on your own machine, but if
    that is the case you have bigger problems anyway.
    
    
    Seth M. McGann / smmat_private        "Security is making it
    http://www.wpi.edu/~smm              to the bathroom in time."
    KeyID: 2048/1024/E2501C80
    Fingerprint 3344 DFA2 8E4A 977B 63A7  19E3 6AF7 4AE7 E250 1C80
    



    This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 14:16:41 PDT