As the return value of ERC1155.balanceOf was changed to a signed integer, the nERC1155Interface does not implement the ERC1155 interface and the supportsInterface call will return false if people call it with the actual ERC1155 interface ID.
Impact
Not all users of the contract might care about the balance function and call supportsInterface with the original EIP1155 interface.
The contract will still deny the
Recommended Mitigation Steps
It is indeed debatable if this contract should be considered implementing ERC1155 and what the correct return value of supportsInterface(ERC1155.interface) should be for compatibility.
Users need to be aware that this contract is not standard compliant and the supportsInterface call will fail.
Handle
cmichel
Vulnerability details
Vulnerability Details
As the return value of
ERC1155.balanceOfwas changed to a signed integer, thenERC1155Interfacedoes not implement theERC1155interface and thesupportsInterfacecall will return false if people call it with the actualERC1155interface ID.Impact
Not all users of the contract might care about the
balancefunction and callsupportsInterfacewith the original EIP1155 interface. The contract will still deny theRecommended Mitigation Steps
It is indeed debatable if this contract should be considered implementing ERC1155 and what the correct return value of
supportsInterface(ERC1155.interface)should be for compatibility. Users need to be aware that this contract is not standard compliant and thesupportsInterfacecall will fail.