The analogue of the candidate ceiling, one rung up: not "can a site be
enumerated" (96.6%) but "can a deterministic abstract-interpretation model
DECIDE the vulnerability without trusting the LLM". Offline, no model calls.
model_entailed today 2.2% (2/92 web/logic pairs)
model_corroborated, one-hop taint 24% (22/92)
taint reachable, multi-hop 35% (26/74 flow families)
candidate site enumerable 96.6% (for comparison)
The gap between 96.6% and 2.2% is the gap between enumerating and arbitrating,
and it is the finding. The model cannot be a pure arbiter at v1. But the
measurement diagnoses depth, not impossibility: one-hop source resolution
(real taint sits 1-3 binds upstream: q = '...'+id; execute(q)), a closed
literal sink table (misses project wrappers and path/xss/prototype sinks), and
a function-naming gap that eats 20/50 injection pairs. Deepening the taint to
the candidate enumerator's depth-4 chain already moved injection 24% -> 48%.
So the course is a layered arbiter, not a pure one: report model_entailed
where the model proves it (deterministic, no LLM); let the LLM judge but check
its claim against the resolved taint on the ~35% corroboration band (noise
removed there); honest suspicion for the rest, which is where the deferred
execution/differential tier earns its place. Modeling confirmed as abstract
interpretation; SMT reserved for the memory/C tier; concolic avoided.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
