Kasplex KRC-20 signature bypass vulnerability caused the highest loss of 99.6% in the value of the KAS side of the ZEAL and NACHO liquidity pools
Attackers exploited a signature verification bypass vulnerability in the Kasplex KRC-20 off-chain indexer to transfer 186 million ZEAL and 54.398 billion NACHO without holding the private keys of the bridge custody wallet. They executed five forged transactions to mint the tokens through the Igra Labs EVM layer and Kasplex L2, then sold them to the Zealous Swap liquidity pool. The KAS side of the affected liquidity pool experienced a value loss of 94% to 99.6%.Igra has suspended iKAS withdrawals to Kaspa L1 and Hyperlane transfers, and has warned users to avoid bridging KRC-20 tokens, buying ZEAL or NACHO on the L2 DEX, and adding liquidity to the related pools. The Kaspa L1 consensus and unbridged Igra assets were not affected. Zealous Swap stated that the operators need to fix the indexer and re-index the history, rejecting transactions with empty signatures, abnormal tags, and transactions containing scripts after OP_ENDIF.