When an account_contract instance is created and initialized, it approves the Kakarots native token to Kakarot, in order to allow it to settle native transfers happening within the EVM:
However, Kakarot has a setter that can be called by admins to update the native token used within the EVM:
After this is called, there is no way to re-trigger approval from account_contract that were previously initialized.
As this functionality is likely not intended to ever be used after Kakarot has been deployed, consider implementing an initializer pattern.
Alternatively, consider adding the necessary methods in Kakarot and account_contract to allow the Kakarot contract to force-approve spending of the native token from the account contracts to itself.
Kakarot mitigated:
Status: Mitigation confirmed.
