# OstiumVault::lockDiscount() may revert due to division by 0 Medium · Three Sigma · RWA perpetuals DEX · 19th February, 2024 Finding 3S-OS-L05 of the Ostium security review. - Protocol: https://www.ostium.com/ - Report: /reports/ostium - Source: https://cdn.sanity.io/files/qoqld077/production/a95b9c69e0f65d1d6b0e649f0d62a362358ca8ce.pdf --- ### Description [OstiumVault::lockDiscount()](https://github.com/0xOstium/smart-contracts-threeSigma/blob/audit-feedback/src/OstiumVault.sol#L83) reverts if maxDiscountThresholdP == uint16(100) * PRECISION_2, but the constructor and updateMaxDiscountThresholdP() allow setting it to this value. ### Recommendation Also check for equality by using <= instead of <. ### Status Addressed in [#32af17a](https://github.com/0xOstium/smart-contracts-threeSigma/pull/58/commits/32af17a5919c8e5c6fcc4f04b0e49eb5d0521459). --- Related findings: - [BorrowingVault, if the debt/assets ratio falls too much, liquidators could choose to repay debt equal to the assets at a discount](https://0xsimao.com/findings/fuji-finance-debt-falls-choose-repay): Fuji Finance - [BasicVault::getRedeemRequestOf() will revert as the redeem requests are filled with the wrong indexes](https://0xsimao.com/findings/mitosis-redeem-revert-filled-indexes): Mitosis