Omni, an NFT platform was hacked for about 1,300 ETH. The hacker utilized a reentrancy vulnerability, a known exploit in smart contracts using Solidity in the Omni Protocol,
For an attack, the hacker used NFTs from a collection called Doodles, he deposited NFTs and took wrapped Ethereum as collateral, then utilized a malicious callback function to frontrun buying more Doodle NFTs before liquidating his loan position.
Once the position was closed, the collateral was returned back to the attacker, so he had a remaining amount of borrowed money to buy even more NFTs, then the hacker used the newly acquired NFTs to borrow, even more, WETH, and could withdraw the loan before Omni's smart contract recognized the loan.
The hack drained more than 1,300 ETH from the protocol, however, Omni said that none of the customer funds were affected, as the platform uses its fund in a test mode since it's still considered a beta.
A really really bad news when the market just started to slowly recover, Omni is not small platform, and $1.4 million is not small amount. Even though Omni said that the user money is not affected, the use still now that Omni system is vulnerable, and usually the hacker will cash-out their ETH very soon, it will also affect the crypto market in general.