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

From: Richard Johnson (rdumpat_private)
Date: Sun Jul 20 2003 - 00:20:45 PDT

  • Next message: Philippe Biondi: "Re: Cisco 0-day? [Was: strange protocol scans (and MOBP plug)]"

    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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