Re:CVE-2023-4809: FreeBSD pf bypass when using IPv6
by xorcist on Friday September 08, 2023 @05:04PM
(#37439404)
Fragmentation is a nightmare. There's been lots of unexpected interactions and security bypasses with that over the years.
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Re:CVE-2023-4809: FreeBSD pf bypass when using IPv6
by warbeforepeace on Friday September 08, 2023 @05:35PM
(#37439730)
IPv4 fragmentation was even worse since any device in the middle could fragment packets. IPv6 atleast limits it to the client/host. I still think they should have designed IPv6 to include L4 info in each fragment to avoid having to reassemble to get that data.
Re:CVE-2023-4809: FreeBSD pf bypass when using IPv6
by enrico204 on Friday September 08, 2023 @05:19PM
(#37439583)
Fragmentation is a nightmare in a nightmare: we also discovered that IPv6 fragments reassembly (as implemented by major operating systems) is still plagued by the problem of overlapping fragments. Potentially, you can still bypass IDS/IPS using the same techniques from IPv4...
Shameless plug: we will present these results at ESORICS 2023 :-)