CVE-2024-37153

Evmos is the Ethereum Virtual Machine (EVM) Hub on the Cosmos Network. There is an issue with how to liquid stake using Safe which itself is a contract. The bug only appears when there is a local state change together with an ICS20 transfer in the same function and uses the contract's balance, that is using the contract address as the sender parameter in an ICS20 transfer using the ICS20 precompile. This is in essence the "infinite money glitch" allowing contracts to double the supply of Evmos after each transaction.The issue has been patched in versions >=V18.1.0.

Evmos is the Ethereum Virtual Machine (EVM) Hub on the Cosmos Network. There is an issue with how to liquid stake using Safe which itself is a contract. The bug only appears when there is a local state change together with an ICS20 transfer in the same function and uses the contract's balance, that is using the contract address as the sender parameter in an ICS20 transfer using the ICS20 precompile. This is in essence the "infinite money glitch" allowing contracts to double the supply of Evmos after each transaction.The issue has been patched in versions >=V18.1.0.

Contract balance not updating correctly after interchain transaction in github.com/evmos/evmos

### Summary _Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server._ ### Details We discovered a bug walking through how to liquid stake using Safe which itself is a contract. The bug only appears when there is a local state change together with an ICS20 transfer in the same function and uses the contract's balance, that is using the contract address as the `sender` parameter in an ICS20 transfer using the ICS20 precompile ### Proof of Concept ```solidity // This function does not reduce the contract balance correctly but liquid stakes correctly function transfer( string memory sourcePort, string memory sourceChannel, string memory denom, uint256 amount, string memory receiver, string memory evmosReceiver ) external returns (uint64 nextSequence) { counter += 1; # Only happens when there is a local state update together with an ICS20 Transfer Height memory timeoutHeight = Height(100, 100); string memory memo = buildLiquidStakeMemo(receiver, evmosReceiver); return ICS20_CONTRACT.transfer( sourcePort, sourceChannel, denom, amount, address(this), # this is the sender address which is the contract receiver, timeoutHeight, 0, memo ); } ``` ### Impact This is in essence the "infinite money glitch" allowing contracts to double the supply of Evmos after each transaction. ### Severity Based on [ImmuneFi Severity Classification System](https://immunefisupport.zendesk.com/hc/en-us/articles/13332717597585-Severity-Classification-System) the severity was evaluated to `Critical` since the attack could have lead to create new supply of EVMOS and therefore lead to Direct loss of funds's value. ### Patches The issue has been patched in versions >=V18.1.0. ## For more information If you have any questions or comments about this advisory: Reach out to the Core Team in [Discord](https://discord.gg/evmos) Open a discussion in [evmos/evmos](https://github.com/evmos/evmos/discussions) Email us at [security@evmos.org](mailto:security@evmos.org) for security questions

Evmos es el centro de máquinas virtuales Ethereum (EVM) en Cosmos Network. Existe un problema con la forma de realizar apuestas líquidas utilizando Safe, que en sí mismo es un contrato. El error solo aparece cuando hay un cambio de estado local junto con una transferencia ICS20 en la misma función y usa el saldo del contrato, es decir, usa la dirección del contrato como parámetro del remitente en una transferencia ICS20 usando la precompilación ICS20. Este es, en esencia, el "fallo del dinero infinito" que permite a los contratos duplicar el suministro de Evmos después de cada transacción. El problema se ha solucionado en las versiones >=V18.1.0.