MANTRA Reports Security Incident After Cosmos EVM Integer Underflow Exploit

MANTRA said in an August 20 security incident report that an attacker used a Cosmos EVM integer underflow vulnerability to transfer 720.924 million MANTRA from two addresses. According to Odaily, 600 million tokens came from a burn address and 121 million came from a genesis multisig address. The report said the attack did not involve validator or administrator keys. The vulnerability was fixed on the development branch on May 15 and merged into the release branch on August 19. The first abnormal transfer occurred at 11:06 (UTC+8) on August 21, after which MANTRA Chain was halted at 15:13 (UTC+8) and restarted on August 22 under version v8.4.0. MANTRA said 683 million of the stolen tokens were sent to exchange deposit addresses, while 37.96 million were frozen. The recovery of funds has entered a law enforcement investigation stage.