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

    > Unless its a private network with locked vaults for the pipes, any
    > network is vulnerable. I am not trying to downplay the relevance of
    > this; all i am saying is it may a little overhyped with the media being
    > involved. Its infact harder to create this attack compared to a simple
    > SYN attack.
    Not quite. With a SYN you have to respond with exactly the same sequence
    number as attacking host in order to establish connection. With RST, your
    sequence number needs to be +- rwin in order to kill the connection. That
    significantly reduces search space.

    > Unless i misunderstood: You need someone/thing to see about 64K packets
    > within a single flow to make the predicition so the attack is succesful.
    > Sure to have access to such capability is to be in a hostile path, no?
    > ;->
    No, you do not need to see any packet.

    > > And it's not BGP specific. You might be able to use this attack to
    > > split IRC networks, too. However, it's a bit harder in this case
    > > because IRC servers usually use more random source ports.
    > Any long lived flow with close to fixed ports. FTP from could
    > be vulnerable - get a better client and its just becomes a nuisance. 80%
    > of the internet traffic is still TCP/HTTP1.0 which is very short lived
    > (there could be changes lately - these are numbers from a while back)
    > i.e you wont see more than 8 packets i.e it is highly unlikely your
    > traffic there is affected even if you used fixed ports.
    Inter-provider BGP is long-lived with close to fixed ports, which is why
    it has caused quite a stir.

    Nevertheless, number of packets to kill the session is still *large*
    (under "best-case" for attacker, you need to send 2^30 packets)...


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