{
 "finding_id": "DF-3294",
 "status": "reproduced",
 "reproduced": 1,
 "poc_path": "findings/poc/DF-3294",
 "artifact_dir": "findings/poc/DF-3294",
 "build_cmd": "cc -O -o <prog> <prog>.c   (on the guest)",
 "run_cmd": "300 (root)",
 "code_hash": "0d6ec5b2ed4465dfbe733fd267aa32c2310dd3fd7eb028e7caa016bfe1e2859c",
 "build_log": "(inline)",
 "run_log": "live1.log",
 "impact": "denial_of_service",
 "confidence": "certain",
 "verdict": "No challenge-ACK rate limiting exists anywhere in tcp_input.c (grep -i challenge: zero hits; no sysctl either). Live measurement on lo0: 300 spoofed out-of-window segments produced 304 ack-only packets (netstat counter delta) - a 1:1 ACK amplification with zero limiting (CVE-2016-5696 family: unthrottled ACK side channel enables off-path RST/SYN injection inference).",
 "exploit_chain": "",
 "evidence": "live1.log DF-3294 section: ack-only delta=304 for 300 OOW segments; tcpdump saw 303 pkts from server",
 "kernel_refs": [
  "sys/netinet/tcp_input.c:2563-2600"
 ],
 "poc_changes": "",
 "attempts": 3,
 "guest_uname": "DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026  root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64",
 "runtime_sec": 60,
 "guest_dirty": 0,
 "runner": "df-bsd-reviewer",
 "notes": "",
 "recommended_fix": "fix.diff",
 "fix_status": "not_testable",
 "fix_verdict": "Upstream-style fix = challenge-ack limiter (per-second budget, sysctl net.inet.tcp.ack_challenge_limit) at the dropafterack ACK emission; kernel not rebuilt for this Low/remote-hardening item.",
 "fix_baseline_reproduced": null,
 "fix_patched_reproduced": null
}