NRDAX-T0401 - Boundary-Check Off-By-One Index OOB Panic
compute_amp · active · first seen 2026-07-17
provenance: Reproduced in NullRabbit's attack-reproduction pipeline
mechanism
The node's proposal-ingest path bounds-checks an attacker-supplied `signer` slot index against the validator-set size using a strict `>` comparison instead of `>=`, so the boundary value `signer == num_validators` passes the check. That value is then used to index the validator array via `get_validator_by_slot_band`, causing an out-of-bounds access, and this happens before any signature verification, so an unauthenticated peer can gossip a single crafted, unsigned proposal to crash every receiving validator. Fix-class: correct the off-by-one bound check (or otherwise validate/clamp the index) prior to array indexing, closing the pre-auth OOB panic (CWE-125/193).
instances (2)
related (compute_amp)
cite
https://nrdax.com/techniques/NRDAX-T0401
NRDAX Registry. Technique NRDAX-T0401.
@misc{nrdax_NRDAX_T0401,
title = {Boundary-Check Off-By-One Index OOB Panic (NRDAX-T0401)},
howpublished = {NRDAX Registry},
url = {https://nrdax.com/techniques/NRDAX-T0401},
} {
"id": "nrdax-NRDAX-T0401",
"type": "dataset",
"title": "Boundary-Check Off-By-One Index OOB Panic (NRDAX-T0401)",
"URL": "https://nrdax.com/techniques/NRDAX-T0401",
"publisher": "NRDAX Registry"
} [](https://nrdax.com/techniques/NRDAX-T0401-boundary-check-off-by-one-index-oob-panic)
use from the CLI
Retrieve or cite this technique from a script or the terminal with the NRDAX Python library & CLI.
nrdax get NRDAX-T0401 nrdax cite NRDAX-T0401 --format bibtex