DittoETH

Summary

Even if the function follows the best practice of check-effects-interaction, not using a reentrancy guard when there may be transfer hooks will open the users of this protocol up to read-only reentrancies with no way to protect against it, except by block-listing the whole protocol.

Vulnerability Details

https://github.com/Cyfrin/2023-09-ditto/blob/main/contracts/facets/ERC721Facet.sol#L162

state change after the call

Impact

The impact of not using a reentrancy guard in this context can be significant. It exposes users of this protocol to potential read-only reentrancy attacks without an easy way to protect against them, aside from block-listing the entire protocol. Read-only reentrancy attacks can lead to unauthorized access to contract state and potentially allow malicious actors to exploit vulnerabilities for malicious purposes.

Tools Used

Manual Revew

Recommendations

Add nonreentrancy modifier of OZ or solmate