Description:

LendingPool contract attempts to receive NFTs from users in depositNFTfunction using safeTransferFrom():

However, the contract does not implement required onERC721Received function to handle NFTs. When safeTransferFrom() is called, it checks if the recipient contract implements this function by trying to call onERC721Received(). Since LendingPool doesn't implement it, all NFT deposit attempts will revert.

This creates a critical issue where the core NFT deposit functionality of the protocol is completely broken - users cannot deposit their NFTs into the lending pool.

Impact:

• Core protocol functionality (NFT deposits) is completely broken

• Users cannot use their NFTs as collateral

• Protocol cannot generate any lending activity

• Affects all users trying to deposit NFT

Recommended Mitigation:

Add onERC721Received()to LendingPool contract