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    SubjectRe: tcp vulnerability? haven't seen anything on it here...
    On Thu, 22 Apr 2004, Giuliano Pochini wrote:

    >
    > On 21-Apr-2004 David S. Miller wrote:
    > > On Wed, 21 Apr 2004 19:03:40 +0200
    > > Jörn Engel <joern@wohnheim.fh-wedel.de> wrote:
    > >
    > >> Heise.de made it appear, as if the only news was that with tcp
    > >> windows, the propability of guessing the right sequence number is not
    > >> 1:2^32 but something smaller. They said that 64k packets would be
    > >> enough, so guess what the window will be.
    > >
    > > Yes, that is their major discovery. You need to guess the ports
    > > and source/destination addresses as well, which is why I don't
    > > consider this such a serious issue personally.
    >
    > Yes, but it is possible, expecially for long sessions. Also,
    > data injections is also possible with the same method, because
    > the receiver accepts everything inside the window, which is
    > usually 64k. Out of curiosity: in case Linux receives two
    > packets relative to the same portion of the stream, does it
    > check if the overlapping data is the same ? It would add extra
    > security about data injection in case the data has not been
    > sent to userspace yet.
    >
    >

    Has anybody checked to see what Linux does if it receives a
    RST to the broadcast address? It would be a shame if all
    connections were dropped!


    Cheers,
    Dick Johnson
    Penguin : Linux version 2.4.26 on an i686 machine (5557.45 BogoMips).
    Note 96.31% of all statistics are fiction.


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