DeFi Protocol Hacker Returns $1.6M Following Pricing Oracle Glitch

The bug allowed the hacker to borrow $1.6 million despite depositing just one GMX token worth $70.

AccessTimeIconMar 10, 2023 at 11:15 a.m. UTC
Updated May 9, 2023 at 4:10 a.m. UTC
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A white hat hacker who targeted decentralized-finance (DeFi) platform has returned $1.6 million that was stolen on Tuesday, receiving a 62.15 ether (ETH) bug bounty worth $850,000 instead.

The attack occurred after upgraded its price feed to relay data from a Chainlink pricing oracle as opposed to a time-weighted average price (TWAP).'s code, which was audited by PeckShield, contained an error and returned a number with too many zeros behind it. That meant the attacker was able to deposit one GMX token, worth around $70, effectively tricking the system into allowing infinite borrows, according to a postmortem published on's Medium page. There was no issue with the Chainlink oracle itself.

After extracting $1.6 million from the protocol, the hacker left an on-chain message: "It looks like your oracle was misconfigured. Contact me to sort this out." reached out and agreed to pay the white hat hacker the bug bounty.

The protocol plans to deploy a new rewritten oracle contract before unpausing borrowing. It has also vowed to repay any unpaid debt left behind by the hacker.

The TND token, which plunged by 34% on Tuesday, was recently trading at $1.87. It has increased by 2.4% in the past 24-hours against its ethereum pair but remains down by 7.6% against its U.S. dollar pair following a crypto market rout.

UPDATE (March 10, 2023, 14:08 UTC): Updates headline and clarifies in second paragraph that the bug was related to's code and not the Chainlink oracle.


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Oliver Knight

Oliver Knight is a CoinDesk reporter based between London and Lisbon. He does not own any crypto.

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