Platform: Code4rena
Start Date: 07/09/2022
Pot Size: $20,000 CANTO
Total HM: 7
Participants: 65
Period: 1 day
Judge: 0xean
Total Solo HM: 3
Id: 159
League: ETH
Rank: 63/65
Findings: 1
Award: $39.22
🌟 Selected for report: 0
🚀 Solo Findings: 0
🌟 Selected for report: lukris02
Also found by: 0x040, 0x1f8b, 0x52, 0xA5DF, 0xNazgul, 0xSky, Bnke0x0, Bronicle, CertoraInc, Chom, CodingNameKiki, Deivitto, Diraco, Dravee, EthLedger, IgnacioB, JC, JansenC, Jeiwan, R2, RaymondFam, ReyAdmirado, Rolezn, SinceJuly, TomJ, Tomo, Yiko, a12jmx, ajtra, ak1, codexploder, cryptphi, csanuragjain, erictee, fatherOfBlocks, gogo, hake, hansfriese, hickuphh3, ignacio, ontofractal, oyc_109, p_crypt0, pashov, peritoflores, rajatbeladiya, rbserver, rokinot, rvierdiiev, tnevler
242.8216 CANTO - $39.22
https://github.com/code-423n4/2022-09-canto/blob/65fbb8b9de22cf8f8f3d742b38b4be41ee35c468/src/Swap/BaseV1-periphery.sol#L525-L534 https://github.com/code-423n4/2022-09-canto/blob/65fbb8b9de22cf8f8f3d742b38b4be41ee35c468/src/Swap/BaseV1-periphery.sol#L537-L546
Tokens with token.decimals > 18 will experience precision loss and return an incorrect price
return price * 1e18 / decimals;
When token.decimals > 18, the above line will experience precision loss because decimals > 1e18. This precision loss will cause BaseV1-periphery.sol#getPriceCanto and getPriceNote to return an incorrect price.
Disable oracle functionality on tokens where token.decimals > 18
#0 - nivasan1
2022-09-10T16:41:58Z
Chain governance is able to determine which tokens will be supported in the lending market. These are the only tokens whose prices will be calculated from the getUnderlyingPrice method in the router. As such, it is not expected that many tokens with > 18 decimals will be supported. Furthermore, for any noticeable loss of precision resulting from this calculation to exist, the token would need to be worth ~< 1/1000 USD, in which case, it is not clear why it would be supported in the lending market.
#1 - 0xean
2022-09-12T13:09:38Z
downgrading to QA, warden doesn't demonstrate a clear attack path of any significant value to the system with the identified loss or precision.