The Root Cause Of Poly Network Being Hacked

The details of the attack

1. The core of this attack is that the verifyHeaderAndExecuteTx function of the EthCrossChainManager contract can execute specific cross-chain transactions through the _executeCrossChainTx function.

Process

1. Attacked contract:

Summary

This attack is mainly because the keeper of the EthCrossChainData contract can be modified by the EthCrossChainManager contract, and the verifyHeaderAndExecuteTx function of the EthCrossChainManager contract can execute the data passed in by the user through the _executeCrossChainTx function. Therefore, the attacker uses this function to pass in carefully constructed data to modify the keeper of the EthCrossChainData contract. It is not the case that this event occurred due to the leakage of the keeper’s private key.

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SlowMist is a Blockchain security firm established in 2018, providing services such as security audits, security consultants, red teaming, and more.

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