Submitted by IllIllI, also found by IllIllI, rbserver, erictee, Trust, hansfriese, skinz, skinz, Franfran, 0xNazgul, ujamal_, Jeiwan, imare, __141345__, __141345__, rbserver, 0x52, gzeon, rvierdiiev, RaymondFam, Rolezn, Lambda, seyni, and codecustard
If the feeders havent updated their prices within the default six-hour time window, the floor oracle will revert when requests are made to get the current price, and these reverts are not caught by the wrapper oracle which handles the fallback oracle, so rather than using the fallback oracle in these cases, the calls will revert, leading to liquidations to fail (see my other submission for the full chain from the floor oracle to the liquidation function).
Additionally, the code uses the deprecated chainlink latestAnswer() API for its token requests, which may revert once it is no longer supported
getPrice() will fail if the values are stale:
https://github.com/code-423n4/2022-11-paraspace/blob/c6820a279c64a299a783955749fdc977de8f0449/paraspace-core/contracts/misc/NFTFloorOracle.sol#L236-L248
They can be stale due to too much price skew, or the feeders being down, e.g. due to another bug:
https://github.com/code-423n4/2022-11-paraspace/blob/c6820a279c64a299a783955749fdc977de8f0449/paraspace-core/contracts/misc/NFTFloorOracle.sol#L369-L372
https://github.com/code-423n4/2022-11-paraspace/blob/c6820a279c64a299a783955749fdc977de8f0449/paraspace-core/contracts/misc/NFTFloorOracle.sol#L376-L386
The wrapper oracle does not use a try-catch, so it cant swallow these reverts and allow the fallback oracle to be used:
https://github.com/code-423n4/2022-11-paraspace/blob/c6820a279c64a299a783955749fdc977de8f0449/paraspace-core/contracts/misc/ParaSpaceOracle.sol#L114-L136
Use a try-catch when fetching the normal latestAnswer(), and use the fallback if it failed.
