[Bug 287229] IP reassembly issue in FreeBSD 14.1
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Date: Fri, 20 Jun 2025 10:03:19 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=287229 --- Comment #24 from Lucas Aubard <lucas.aubard@irisa.fr> --- (In reply to Michael Tuexen from comment #18) Thanks for the details! We are currently working on Network Intrusion Detection Systems (NIDS) evasion with overlapping IP fragments or TCP segments. Some NIDSes (Suricata, Snort) propose configuring their IP and TCP reassemblies based on the supervised host OSes as an evasion countermeasure to overlapping-based attacks. In that context, we test OSes (and other stacks) to obtain and describe their reassembly policies so NIDSes can implement and propose them. From a NIDS perspective, OS reassembly consistency is thus quite important. We recently wrote a paper on that subject https://arxiv.org/pdf/2504.21618 (that will appear at DIMVA'25) if you want more details. The 40 processes do not correspond to any particular real situation I would try to reproduce. As I mentioned, I test OS VMs simultaneously if possible, and 40 processes is a good tradeoff between the time it takes for the entire experiment to finish and the number of VMs I can run in parallel. -- You are receiving this mail because: You are on the CC list for the bug.