Ethermint is an Ethereum library. In Ethermint running versions before `v0.17.2`, the contract `selfdestruct` invocation permanently removes the corresponding bytecode from the internal database storage. However, due to a bug in the `DeleteAccount`function, all contracts that used the identical bytecode (i.e shared the same `CodeHash`) will also stop working once one contract invokes `selfdestruct`, even though the other contracts did not invoke the `selfdestruct` OPCODE. This vulnerability has been patched in Ethermint version v0.18.0. The patch has state machine-breaking changes for applications using Ethermint, so a coordinated upgrade procedure is required. A workaround is available. If a contract is subject to DoS due to this issue, the user can redeploy the same contract, i.e. with identical bytecode, so that the original contract's code is recovered. The new contract deployment restores the `bytecode hash -> bytecode` entry in the internal state.

Cronos is a commercial implementation of a blockchain. In Cronos nodes running versions before v0.6.5, it is possible to take transaction fees from Cosmos SDK's FeeCollector for the current block by sending a custom crafted MsgEthereumTx. This problem has been patched in Cronos v0.6.5. There are no tested workarounds. All validator node operators are recommended to upgrade to Cronos v0.6.5 at their earliest possible convenience.

Cosmos Network Ethermint <= v0.4.0 is affected by cache lifecycle inconsistency in the EVM module. The bytecode set in a FAILED transaction wrongfully remains in memory(stateObject.code) and is further written to persistent store at the Endblock stage, which may be utilized to build honeypot contracts.

Cosmos Network Ethermint <= v0.4.0 is affected by a transaction replay vulnerability in the EVM module. If the victim sends a very large nonce transaction, the attacker can replay the transaction through the application.

Cosmos Network Ethermint <= v0.4.0 is affected by cache lifecycle inconsistency in the EVM module. Due to the inconsistency between the Storage caching cycle and the Tx processing cycle, Storage changes caused by a failed transaction are improperly reserved in memory. Although the bad storage cache data will be discarded at EndBlock, it is still valid in the current block, which enables many possible attacks such as an "arbitrary mint token".

Cosmos Network Ethermint <= v0.4.0 is affected by a cross-chain transaction replay vulnerability in the EVM module. Since ethermint uses the same chainIDEpoch and signature schemes with ethereum for compatibility, a verified signature in ethereum is still valid in ethermint with the same msg content and chainIDEpoch, which enables "cross-chain transaction replay" attack.