DF-3390 / verdict.json
{ "finding_id": "DF-3390", "status": "not_reproduced", "reproduced": 0, "impact": "none", "confidence": "certain", "verdict": "Line-accurate confirmation; a timing side-channel measurement is not meaningfully demonstrable on this rig (and the accept/reject oracle already exists). noise_consume_initiation compares the decrypted TAI64N timestamp with plain memcmp (wg_noise.c:1143) while the same file uses timingsafe_bcmp for public-key/psk comparisons (:503, :651, :1499); OpenBSD hardened this site to fixedtime_bcmp. Functionally correct (big-endian lexicographic == numeric) - defense-in-depth only. Fix adds a constant-time sign-compare helper (noise_tai64n_cmp); compile-validated by building sys/net/wg against the patched tree (module build; wg is not in the F40FIX kernel).", "exploit_chain": "", "evidence": "VERDICT.md with path:line citations; run.log where a live demo exists; fix.diff", "kernel_refs": [ "sys/net/wg/wg_noise.c:1143", "sys/net/wg/wg_noise.c:503" ], "poc_changes": "n/a - timing channel, no runnable demonstration", "attempts": 0, "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": 15, "guest_dirty": 0, "build_cmd": "see build.sh", "run_cmd": "see run.sh", "code_hash": null, "notes": "", "recommended_fix": "constant-time noise_tai64n_cmp() replaces memcmp at the replay check", "fix_status": "compile_validated", "fix_verdict": "compile-validated by building sys/net/wg from the patched tree (if_wg.ko, rc=0, zero errors). No runtime A/B (timing channel)." } |