Part 2

Summary

ERC-7201 (formerly EIP-7201) is a standard for grouping storage variables together by a common identifier called a namespace, and also to document the group of variables via NatSpec annotation. The purpose of the standard is to simplify managing storage variables during upgrades.

The formula proposed above is used to guarantee a crucial property of the new root: that it does not collide with an original grammar element — i.e. the possible space of storage locations the Solidity compiler could assign a variable to by default.

Tree Proxy Pattern is our novel modular, and opinionated proxy pattern solution designed to address key industry problems faced by large smart contract systems, by introducing the following solutions:

• Simplified terminology (Compared to e.g EIP-2535)

• EIP-7201 compatible

• Clear testing paths (leveraging BTT)

• Composability over inheritance

• Upgradeability

Vulnerability Details

Contracts Affected in leaves directory:
```

│ ├── leaves/
│ │ ├── AssetSwapPath.sol
│ │ ├── Collateral.sol
│ │ ├── CreditDelegation.sol
│ │ ├── DexSwapStrategy.sol
│ │ ├── Distribution.sol
│ │ ├── LiveMarkets.sol
│ │ ├── Market.sol
│ │ ├── MarketMakingEngineConfiguration.sol
│ │ ├── StabilityConfiguration.sol
│ │ ├── Swap.sol
│ │ ├── UsdTokenSwapConfig.sol
│ │ ├── Vault.sol
│ │ └── WithdrawalRequest.sol

```

Implemented codes specified ERC-7201 but was not implemented correctly. The full formula is keccak256(keccak256(namespace) - 1) & ~0xff. It is missing the & ~0xff for all the contracts in leaves directory.

Performing the AND NOT 0xff operation transforms the rightmost byte of the location to 00. This prepares for a future upgrade when Ethereum switches its storage data structure to Verkle Trees and 256 adjacent slots can be warmed at once.
E.g in AssetSwapPath.sol:

Impact

There can be storage slot issues when Ethereum hard forks, causing the protocol to have potential storage collision due to upgrades.

Tools Used

Recommendations

Include the & ~0xfffor all contracts implemented in leaves directory.