Submitted by sseefried, also found by 0x4non, arcoun, berndartmueller, cccz, csanuragjain, IllIllI, Jmaxmanblue, JohnSmith, Lambda, minhquanym, rbserver, and rotcivegaf
ERC721.sol#L395-L417
While VoteEscrowCore.safeTransferFrom does try to call onERC721Received on the receiver it does not check the for the required magic bytes which is IERC721.onERC721received.selector in this case. See OpenZeppelin docs for more information.
Its quite possible that a call to onERC721Received could succeed because the contract had a fallback function implemented, but the contract is not ERC721 compliant.
The impact is that NFT tokens may be sent to non-compliant contracts and lost.
Lines 604 - 605 are:
but they should be:
Implement safeTransferReturn so that it checks the required magic bytes: IERC721Receiver.onERC721Received.selector.
zeroexdead (Golom) confirmed
zeroexdead (Golom) commented:
0xsaruman (Golom) resolved, but disagreed with severity
