Ethereum mempool delisting data from the OpenSea non-fungible token trading platform was used to buy NFTs ahead of time.
The story of a critical vulnerability in the OpenSea interface, which made it possible to purchase tokens at reduced prices, continued.
On January 27, the platform sent out a special email to users who still have inactive lists of NFTs for sale in their accounts. It was explained to addressees on behalf of OpenSea that the platform will not be able to cancel the lists on its own behalf and asks users to do it themselves. Otherwise, orders to buy NFTs at a reduced price can still be executed. The letter stated that delisting “will prevent any of your items from being sold at an inactive price.”
2/ This is the email that Opensea sent out a few hours ago to users who still had “inactive listings” on their accounts. Basically they are asking you to cancel old listings that you have on your NFTs that are still fulfillable, because they are unable to cancel them for you. pic.twitter.com/Fgd854Dezj
– dingaling (@dingalingts) January 27, 2022
However, according to users who heeded OpenSea’s call, the recommendation had the opposite effect. The delisting resulted in the re-creation of the original order. As a result, some of the token holders stated that they had lost both their NFTs and their money.
User @swolfchan.eth wrote tweeted that he had lost at least 15 ETH by following OpenSea’s recommendations. Following the delisting, the NFT called Mutant Ape Yacht Club was re-listed for the old price of 6 ETH instead of the current 21 ETH.
Similar situation happened with user MJ129.ETH. His Bored Ape Yacht Club NFT was sold at the old listing price of 24 ETH, instead of the 135 ETH price set by the user later.
In both cases, an unidentified person discovered a pending cancellation transaction in the ETH mempool, and the NFT was instantly bought in the same block, ahead of the cancellation operation.
OpenSea has yet to respond to @swolfchan.eth’s question as to whether he and other victims will be eligible for damages.