stateObject
: represents the state of an account and is used to store its updates during a state transition. This is accomplished using two in memory Storage variables: originStorage
and dirtyStorage
StateDB
: it is the general interface to retrieve accounts and holds a map of stateObjects.An external contributor, @iczc, discovered 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.
Below, are described the steps to perform the attack:
originStorage
. If the tx is executed correctly, this is what happens at the store level:
dirtyStorage
is committed to the KVStore without changing the originStorage
.dirtyStorage
, it is updated to the previous value A without changing the originStorage
.Since the tx executed correctly, the evm calls the commit to persist the dirtyStorage. However, since dirtyStorage is equal to originStorage, nothing will be changed.
To summarize, 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.
Based on ImmuneFi Severity Classification System the severity was evaluated to Critical
since the attack could have lead to direct loss of funds.
The issue has been patched in versions >=V17.0.0.
If you have any questions or comments about this advisory:
Reach out to the Core Team in Discord Open a discussion in evmos/evmos Email us at security@evmos.org for security questions
{ "nvd_published_at": "2024-04-19T15:15:50Z", "cwe_ids": [ "CWE-662" ], "severity": "CRITICAL", "github_reviewed": true, "github_reviewed_at": "2024-04-10T22:04:30Z" }