Using Java from Javascript

Date: 04/02/03

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    Date:         Tue, 1 Apr 2003 22:46:26 -0300
    From: idoru@VIDEOSOFT.NET.UY

    Opera and Netscape browsers allow you to include java methods calls in
    your javascript . As Javascript has support for objects you can use
    objects returned by these calls in your scripts .
    I have been looking for information about the possibly security
    implications ( and vulnerabilities published ) that this could have , but
    have found nothing . Doing some test by myself this is but I have found .
    Opera 6.01

    If you use Opera 6.01 you can make calls to Java exec function , which
    executes the command line passed to it . This means you can execute any
    program . Here is a small demonstration

    The second link executes windows calculator . The first link executes
    verifier.exe , a W2000/XP program , causing a buffer overflow in it (
    W2000 server is full of command line buffer overflows ), this means that
    just visiting a webpage ( a malicious site or a post in a forum ) code can
    be executed in your machine with user priviliges .
    Besides , playing with sockets from javascript you can obtain the local Ip
    address with

    and use it to connect to an arbitrary local tcp port on your IP . If you
    are connected to a LAN , you can connect with every socket in your LAN
    interface.This means that with viewing some post in a forum , a script can
    connect to a port on your PC and send and recieve data ( as classes like
    InputDataStram can be used as well ). A new type of cross site scripting
    focused in exploiting vulnerable services .
    An example can be found here , connection to port 139 can be tracked with
    netstat ( before closing the browser )

    Opera 7.02 and Netscape 7.02

    Both browsers donīt allow to make java calls to determinate methods . Well
    , are allowed by they return a null . You can`t execute exec or delete ,
    just methods like or but you can
    still execute sockets .
    Fourtunately , I wasnīt able of retriving another IP different from
    localhost when the script is executed in the server , but it works fine if
    you email the webpage , establishing the connection with port 139 . Just
    open the file attached and click the link . I donīt know if there is an
    alternative method of retrieving a visitor's IP address from java or
    javascript but if there is this can be exploitable via webpage .

    Regards ,

    David F.Madrid ,
    Madrid , Spain

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