[Full-disclosure] SA Security Bulletin: Zorch Vulnerability in Rhino Snarf Java Interpretor

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Date: 09/30/05

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    _________________________________________________________________

                      Sexy Action Security Bulletin
            
                        SASB-2005-09-30-GR8-2B-EL8

           Zorch Vulnerability in Rhino Snarf Java Interpreter

    _________________________________________________________________

            Platform: GibsonOS
            CPU Type: Any
            Package: Rhino Snarf Pharynx
            Affected Versions: 2.1 (current) and earlier
            Vulnerability Type: c|n>k, wirewater overflow, death
            Severity (1-10): 10
            Author: @pex p01zen

    Executive Summary:

    Rhino Snarf is a popular peer-to-peer client used for packet
    sniffing, wirewater communication, and downloading non-physical
    data over a wide area network such as the internet. This
    vulnerability affects versions 2.1 (current) and earlier,
    running on any GibsonOS system.

    A Zorch Vulnerability that exists in the Snarf Protocol is
    capable of rendering any unprotected CPU useless via a wirewater
    buffer overflow through Pharynx, which is packaged with Rhino
    Snarf by default.

    Several workarounds are suggested at the end of this document.

    Problem Statement:

    When Rhino Snarf uses the Wirewater Protocol to communicate over
    WAN, it normally only calls on Pharynx to send overflow data to
    the keyboard or monitor. Pharynx buffer overflows (outgoing) are
    by no means a new concept; since Rhino Snarf only allows
    Wirewater data to flow -out- of Pharynx, the attack is single and
    limited to the size of the buffer.

    However a system glitch can cause Rhino Snarf and Pharynx to
    sniff Java packets without any means of processing them. This in
    turn causes the user to send -and- receive Java packets over an
    insecure protocol not designed to handling incoming connections.

    Miscommunication of data type results in an autosomal dominant
    compelling helio-ophthalmic outburst from Pharynx. When used in
    conjunction with Wirewater this can return a c|n>k type attack on
    your computer. However, if the system's CPU is unprotected, Java
    data flowing from Pharynx can cause a Zorch attack on your CPU.
    This renders the CPU useless through overheating.

    Exploit Method:

    On our test systems, we tricked Rhino Snarf into receiving Java
    packets through Pharynx. This intake caused Rhino Snarf to choke
    on its own data. As expected, a high level of system instability
    was experienced before the helio-opthalmic outburst was detected.

    At a low data level this resulted in the predicted c|n>k attack.

    However, if Pharynx is also receiving Java packets at the time of
    the outburst, the overflow from Rhino Snarf is much greater
    (since outflow is no longer limited to the size of the buffer).

    To test this, Java packets were received through two open Pharynx
    ports at once. Rhino Snarf, unable to process the information,
    not only caused a autosomal dominant compelling helio-ophthalmic
    outburst, but the direction, velocity, and size of the attack saw
    data sent directly to the CPU. Excess Java packets caused the
    CPU fan to short-circuit and die. The CPU Heatsink was then next
    as it conducted the excessive heat towards the CPU. Overwhelming
    amounts of data spilled out onto the Motherboard at which point
    it became impossible to monitor the system due to a total CPU
    Zorch.

    System Death was recorded at approximately 5.3 seconds after the
    miscommunication began.

    Fix:

    There are number of methods for preventing this attack, however
    once 2 port miscommunication to Pharynx has occurred, very little
    can be done to stop the attack in progress. Based on research by
    our team of security professionals, it is suggested that users
    block all incoming Java connections on the Rhino Snarf port and
    ensure their computer case is properly constructed.
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