Signed/unsigned arithmetic confusion
Sky Lending (formerly MakerDAO)'s assessment for RD-F-018 — scored green on the v1.7.0 rubric. The evidence below is the curator's reasoning for this score.
Evidence summary #
Vat frob() accepts int256 parameters with explicit signed/unsigned conversion via custom _add(uint,int) helper. This pattern reviewed by ToB 2019 with no overflow issues found. Endgame contracts use Solidity 0.8.x with native overflow protection.
Sources #
- URLhttps://github.com/makerdao/mcd-security/blob/master/Audit%20Reports/TOB_MakerDAO_Final_Report.pdfretrieved 2026-04-27
- https://github.com/sky-ecosystem/dss/blob/master/src/vat.solretrieved 2026-04-27
Methodology #
Determine whether signed-integer conversions or comparisons where unsigned was intended exist in the deployed bytecode/source.
See the full factor methodology and distribution across all protocols →
rubric_version v1.7.0 protocol sky-lending factor RD-F-018 score green collected_at 2026-04-28 00:43:18