A misconfiguration in the iBTC/aUSD liquidity pool's incentive mechanism allowed unlimited minting of aUSD tokens instead of LP tokens. Over 1.2 billion aUSD were minted before the network was paused and funds recovered.

The Polkadot ecological project Acala caused an additional issuance of aUSD due to an error on the chain, allowing attackers to mint aUSD. The vulnerability caused aUSD to lose its peg to the US dollar, initially falling to $0.60 and hovering around $0.90. Acala suspended the protocol shortly after the attack and disabled the transfer of the stolen aUSD and the attackers exchanging Acala tokens for some of the aUSD.