Summary

The contract HorseStore.sol is set to be deployed on Arbitrum chain but the solidity version 0.8.20 has opcode PUSH0 which is not supported on Arbitrum, thus it cannot be deployed.

Vulnerability Details

The concern is regarding the usage of solc version 0.8.20 in the smart contract. The version exhibits the PUSH0 opcode and is currently not supported across all EVM chains. The contract is required to be deployed on Arbitrum chain, but it doesn't support the PUSH0 opcode (ref. Arbitrum documentation https://docs.arbitrum.io/for-devs/concepts/differences-between-arbitrum-ethereum/solidity-support). The vulnerability here is that the contracts compiled with solidity versions above 0.8.19 will not be able to deploy, or even if they are able to deploy then may not function properly and may lead to other consequences.

Impact

The impact of using the solidity version 0.8.20 is that it comes with the PUSH0 opcode and this opcode is not supported on Arbitrum causing the smart contract to malfunction and the contract may not execute correctly.

Tools Used

Aderyn tool.

Recommendations

PUSH0 opcode comes with 0.8.20 and higher versions, therefore switching to 0.8.19 will make the smart contract fully compatible to be deployed on Arbitrum chain.

• HorseStore.sol