NOBO denial of service

From: Andrew J. Gavin (gavinaat_private)
Date: Thu Feb 04 1999 - 13:52:00 PST

  • Next message: Ricardo Peres: "Re: Microsoft Access 97 Stores Database Password as Plaintext"

    As reported by i-kranat_private approximately a week ago, nobo (a back
    orifice scanning detector) has a buffer overflow problem that will crash
    the program remotely.  Sending a UDP packet (larger than 1024 bytes) will
    give the error:
    
    A network error has ocurred: Message too long (10040-92)
    
    Sending 15 of these packets (the minimum required) will crash nobo (stack
    fault in kernel32.dll), with NOTHING recorded to the log file or to the
    screen.
    
    I tested this against nobo 1.2 from both Windows 98 and linux, giving the
    same results.  Using 'assault' (included with the mIRC script "7th
    sphere", I believe) in Windows, for example, I was able to send 15 UDP
    packets at 1025 bytes in size, crashing my nobo.  In linux, I was able to
    crash my nobo by echoing a string 1025 characters in length, piping it
    through nc (with the -u flag), and repeating 14 more times.
    
    I'm sure some nice scripts could be written to do this to a class C
    subnet.  The only drawback to this is that it would be rather
    bandwidth-intensive (15 x 1025 bytes x 255).
    
    ----------
    gavinaat_private
    k3nny or ChazeFroy on Efnet IRC
    



    This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 14:32:34 PDT