Messages in this thread | | | From | (David Wagner) | Subject | Re: ack number in a connection-refused RST | Date | 6 Oct 2000 21:06:31 GMT |
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David S. Miller wrote: >Linux should not honor the incorrect sequence number. If the sequence >number is incorrect, the RST could legitimately be for another >connection.
How could it be for another connection, if it has source and destination port numbers? I thought the sequence number was there to prevent denial of service attacks, i.e., to prevent unauthorized third parties from tearing down established TCP connections; since third parties will not know (or be able to guess) the current 32-bit sequence number, they will be unable to forge a valid RST packet. Of course, this argument is still valid even if you accept off-by-one errors in the sequence number; the attacker still has to guess from a 31-bit space, which is slightly smaller than the original 32-bit space but still likely large enough for security. What am I missing? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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