Description

Evmos is a scalable, high-throughput Proof-of-Stake EVM blockchain that is fully compatible and interoperable with Ethereum. Prior to 17.0.0, there is a way to mint arbitrary tokens due to the possibility to have two different states not in sync during the execution of a transaction. The exploit is based on the fact that to sync the Cosmos SDK state and the EVM one, we rely on the `stateDB.Commit()` method. When we call this method, we iterate though all the `dirtyStorage` and, **if and only if** it is different than the `originStorage`, we set the new state. Setting the new state means we update the Cosmos SDK KVStore. If a contract storage state that is the same before and after a transaction, but is changed during the transaction and can call an external contract after the change, it can be exploited to make the transaction similar to non-atomic. The vulnerability is **critical** since this could lead to drain of funds through creative SC interactions. The issue has been patched in versions >=V17.0.0.

Weaknesses 1

Affected Products 1

References 3

• github.com https://github.com/evmos/evmos/blob/b196a522ba4951890b40992e9f97aa610f8b5f9c/x/evm/statedb/statedb.go#L460-L465
  Product
• github.com https://github.com/evmos/evmos/commit/08982b5ee726b97bc50eaf58d1914829648b6a5f
  Patch
• github.com https://github.com/evmos/evmos/security/advisories/GHSA-3fp5-2xwh-fxm6
  Vendor Advisory

Remediation

• github.com https://github.com/evmos/evmos/commit/08982b5ee726b97bc50eaf58d1914829648b6a5f
  Patch