FatMan discovered one instance where a person deposited $10,000 and later withdrew $4.3 million. According to FatMan, they found repeated exploits of this type that earned attackers "well over $30 million". Another researcher on Terra forums estimated about $88 million had been exfiltrated from the project in this way, over the many months the bug went undiscovered and unpatched by Mirror developers.
Researcher discovers vulnerability in the Terra Mirror Protocol that allowed attackers to siphon tens of millions from the project
A crypto researcher who goes by "FatMan" discovered that the Mirror Protocol in the Terra ecosystem contained a serious vulnerability, that was quietly patched with no announcement on May 9. The Mirror Protocol code previously lacked a duplicate check, which meant that attackers could create a short position and then withdraw it repeatedly in the same transaction, taking many times more money than they should have been authorized to withdraw.