Impact
This advisory has been created to address the following vulnerabilities found in the Evmos codebase and affecting vesting accounts.
Wrong spendable balance computation
The spendable balance is not updated properly when delegating vested tokens. The following example help in describing the issue:
- Given a clawback vesting account with a starting
15M vesting schedule. The initial spendable balance is 0.
- Time passes and
5M are vested. The spendable balance is now 5M.
- The account delegate
5M. The spendable balance should be 0, but returns 5M
- The account can send
5M to another account.
The issue allowed a clawback vesting account to anticipate the release of unvested tokens.
Missing precompile checks
Preliminary checks on actions computed by the clawback vesting accounts are performed in the ante handler. Evmos core, implements two different ante handlers: one for Cosmos transactions and one for Ethereum transactions. Checks performed on the two implementation are different.
The vulnerability discovered allowed a clawback account to bypass Cosmos ante handler checks by sending an Ethereum transaction targeting a precompile used to interact with a Cosmos SDK module.
Missing create validator check
This vulnerability allowed a user to create a validator using vested tokens to deposit the self-bond.
Patches
- The spendable balance function has been fixed correcting the
TrackDelegation function.
- The checks for the staking module, for the delegation and the create validator, has been moved into the
MsgServer of a wrapper around the Cosmos SDK staking module.
The issues have been patched in versions >=V18.0.0.
References
- Evmos vesting module
For more information
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 [email protected] for security questions
References
Impact
This advisory has been created to address the following vulnerabilities found in the Evmos codebase and affecting vesting accounts.
Wrong spendable balance computation
The spendable balance is not updated properly when delegating vested tokens. The following example help in describing the issue:
15Mvesting schedule. The initial spendable balance is0.5Mare vested. The spendable balance is now5M.5M. The spendable balance should be0, but returns5M5Mto another account.The issue allowed a clawback vesting account to anticipate the release of unvested tokens.
Missing precompile checks
Preliminary checks on actions computed by the clawback vesting accounts are performed in the ante handler. Evmos core, implements two different ante handlers: one for Cosmos transactions and one for Ethereum transactions. Checks performed on the two implementation are different.
The vulnerability discovered allowed a clawback account to bypass Cosmos ante handler checks by sending an Ethereum transaction targeting a precompile used to interact with a Cosmos SDK module.
Missing create validator check
This vulnerability allowed a user to create a validator using vested tokens to deposit the self-bond.
Patches
TrackDelegationfunction.MsgServerof a wrapper around the Cosmos SDK staking module.The issues have been patched in versions >=V18.0.0.
References
For more information
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 [email protected] for security questions
References