RE: Cisco IOS Denial of Service that affects most Cisco IOS routers- requires power cycle to recover

From: Curt Purdy (purdyat_private)
Date: Sun Jul 20 2003 - 11:58:50 PDT

  • Next message: Richard Johnson: "RE: Cisco IOS Denial of Service that affects most Cisco IOS routers- requires power cycle to recover"

    Could we have an example of an hping command to invoke this.  I have been
    playing with it and would like a real-world example, and since there a now
    multiple exploits out, this knowledge should not be a problem. Thanks.
    
    Curt
    
    ----------------------------------------
    
    Practice safe hex.
    
    - Andrew Briney, editor Information Security
    
    
    -----Original Message-----
    From: Richard Johnson [mailto:rdumpat_private]
    Sent: Sunday, July 20, 2003 2:21 AM
    To: incidentsat_private
    Subject: Re: Cisco IOS Denial of Service that affects most Cisco IOS
    routers- requires power cycle to recover
    
    
    In article
    <Pine.BSO.4.53.0307172223150.11409at_private-guesswork.com>,
     Tina Bird <tbird@precision-guesswork.com> wrote:
    
    > information on the detailed structure of the evil packets in these
    > protocols is not yet public AFAIK.
    
    
    The router has problems if it receives a packet, content irrelevant,
    that makes it to supervisor level claiming an IP protocol that it
    doesn't have code to handle.
    
    The kickup to supervisor level happens when the packet is targeted
    directly at the router's IP address (per first Cisco advisory) or just
    has its TTL expire in transit past the router (per revised Cisco
    advisory).
    
    Send enough packets (default 75), and the input queue is full.  hping is
    enough of a launch platform for that--there's no need for
    questionable-source exploit binaries when testing.
    
    
    Richard
    
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