ERC1155Supply vulnerability in OpenZeppelin Contracts

Summary

When ERC1155 tokens are minted, a callback is invoked on the receiver of those tokens, as required by the spec. When including the `ERC1155Supply` extension, total supply is not updated until after the callback, thus during the callback the reported total supply is lower than the real number of tokens in circulation. ### Impact If a system relies on accurately reported supply, an attacker may be able to mint tokens and invoke that system after receiving the token balance but before the supply is updated. ### Patches A fix is included in version 4.3.3 of `@openzeppelin/contracts` and `@openzeppelin/contracts-upgradeable`. ### Workarounds If accurate supply is relevant, do not mint tokens to untrusted receivers. ### Credits The issue was identified and reported by @ChainSecurityAudits. ### For more information Read [TotalSupply Inconsistency in ERC1155 NFT Tokens](https://medium.com/chainsecurity/totalsupply-inconsistency-in-erc1155-nft-tokens-8f8e3b29f5aa) by @ChainSecurityAudits for a more detailed breakdown. If you have any questions or comments about this advisory, email us at [email protected].