parzival - Stablecoin.sol and AmirX.sol are upgradable contracts but inherit from contracts that does not have storage gap

[sherlock-admin4]

parzival

Medium

Stablecoin.sol and AmirX.sol are upgradable contracts but inherit from contracts that does not have storage gap

Summary

Stablecoin.sol inherits from Blacklist.sol and AmirX.sol inherits from StablecoinHandler.sol both of which contains storage variables but does not have gap variables in them. These gap variables are necessary since the contracts are intended to be upgradable and no gap can lead to storage collisions.

Root Cause

In StablecoinHandler.sol:21 and [Blacklist.sol:14](https://github.com/sherlock-audit/2024-11-telcoin/blob/main/telcoin-audit/contracts/util/abstract/Blacklist.sol#L14) we can see storage variables being created in the parent contracts. If proper gap variables are not added then upgrading these contracts might lead to storage collisions.

Internal pre-conditions

No response

External pre-conditions

No response

Attack Path

No response

Impact

No response

PoC

Already explained in the Summary and root cause.

Mitigation

Add storage gaps to all inherited contracts that contain storage variables.