Overlapping Fragments
An IDS evasion technique is to craft a series of packets with TCP sequence numbers configured to overlap. For example, the first packet will include 80 bytes of payload but the second packet's sequence number will be 76 bytes after the start of the first packet. When the target computer reassembles the TCP stream, they must decide how to handle the four overlapping bytes. Some operating systems will take the older data, and some will take the newer data.
Read more about this topic: Intrusion Detection System Evasion Techniques
Famous quotes containing the words overlapping and/or fragments:
“The absolute things, the last things, the overlapping things, are the truly philosophic concerns; all superior minds feel seriously about them, and the mind with the shortest views is simply the mind of the more shallow man.”
—William James (1842–1910)
“The art of writing books is not yet invented. But it is at the point of being invented. Fragments of this nature are literary seeds. There may be many an infertile grain among them: nevertheless, if only some come up!”
—Novalis [Friedrich Von Hardenberg] (1772–1801)