Lending Protocol Patterns

Audit a lending protocol by systematically checking liquidation logic, interest rate models, collateral handling, and health factor calculations against known vulnerable patterns. This skill provides Solidity code examples of each vulnerability class plus a severity-classified checklist.

Common issues include profitable self-liquidation when the bonus exceeds (100% - max LTV), liquidation cascades from large positions, and unhandled bad debt when collateral value falls below debt. Mitigations include partial liquidation, circuit breakers, and insurance funds.

Attackers use flash loans to temporarily shift utilization rates and borrow at artificially low rates. Precision loss also occurs when small principal amounts round interest to zero, which is mitigated by accumulating interest at high precision such as Ray (1e27).

Yes, it documents common Aave/Compound patterns including reserve factors, supply indices, and jump rate interest models. The checklist applies directly to forks of these protocols and similar lending designs.

It is auto-loaded by the defi-auditor agent during Phase 2 when the target is identified as a lending protocol. It is not user-invocable and serves as reference knowledge for the specialist auditor.