ZKsync

Prize Pool TO BE FILLED OUT BY CYFRIN

• Total Pool - $500,000

• H/M - $475,000

• Low - $25,000

• Starts: October 28, 2024 Noon UTC

• Ends: Dec 02, 2024 Noon UTC

• nSLOC: 15,741

About the Project

ZKsync Era is an EVM compatible layer 2 rollup that uses zero-knowledge proofs to scale Ethereum without compromising on security or decentralization.

Documentation
Website
Twitter
GitHub

Relevant Documentation

Contracts
ZKsync Governance

Scope (contracts)

Era-Contracts

├── da-contracts
│   ├── contracts
│   │   ├── CalldataDA.sol
│   │   ├── DAContractsErrors.sol
│   │   ├── DAUtils.sol
│   │   ├── IL1DAValidator.sol
│   │   ├── IL1Messenger.sol
│   │   └── RollupL1DAValidator.sol
├── l1-contracts
│   ├── contracts
│   │   ├── bridge
│   │   │   ├── BridgeHelper.sol
│   │   │   ├── BridgedStandardERC20.sol
│   │   │   ├── L1BridgeContractErrors.sol
│   │   │   ├── L1ERC20Bridge.sol
│   │   │   ├── L1Nullifier.sol
│   │   │   ├── L2SharedBridgeLegacy.sol
│   │   │   ├── L2WrappedBaseToken.sol
│   │   │   ├── L2WrappedBaseTokenStore.sol
│   │   │   ├── asset-router
│   │   │   │   ├── AssetRouterBase.sol
│   │   │   │   ├── IAssetRouterBase.sol
│   │   │   │   ├── IL1AssetRouter.sol
│   │   │   │   ├── IL2AssetRouter.sol
│   │   │   │   ├── L1AssetRouter.sol
│   │   │   │   └── L2AssetRouter.sol
|   |   │   ├── interfaces
|   |   │   │   ├── IAssetHandler.sol
|   |   │   │   ├── IBridgedStandardToken.sol
|   |   │   │   ├── IL1AssetDeploymentTracker.sol
|   |   │   │   ├── IL1AssetHandler.sol
|   |   │   │   ├── IL1BaseTokenAssetHandler.sol
|   |   │   │   ├── IL1ERC20Bridge.sol
|   |   │   │   ├── IL1Nullifier.sol
|   |   │   │   ├── IL1SharedBridgeLegacy.sol
|   |   │   │   ├── IL2SharedBridgeLegacy.sol
|   |   │   │   ├── IL2SharedBridgeLegacyFunctions.sol
|   |   │   │   ├── IL2WrappedBaseToken.sol
|   |   │   │   └── IWETH9.sol
|   |   │   └── ntv
|   |   │       ├── IL1NativeTokenVault.sol
|   |   │       ├── IL2NativeTokenVault.sol
|   |   │       ├── INativeTokenVault.sol
|   |   │       ├── L1NativeTokenVault.sol
|   |   │       ├── L2NativeTokenVault.sol
|   |   │       └── NativeTokenVault.sol
│   │   ├── bridgehub
│   │   │   ├── Bridgehub.sol
│   │   │   ├── CTMDeploymentTracker.sol
│   │   │   ├── IBridgehub.sol
│   │   │   ├── ICTMDeploymentTracker.sol
│   │   │   ├── IMessageRoot.sol
│   │   │   ├── L1BridgehubErrors.sol
│   │   │   └── MessageRoot.sol
│   │   ├── common
│   │   │   ├── Config.sol
│   │   │   ├── Dependencies.sol
│   │   │   ├── L1ContractErrors.sol
│   │   │   ├── L2ContractAddresses.sol
│   │   │   ├── Messaging.sol
│   │   │   ├── ReentrancyGuard.sol
│   │   │   ├── interfaces
│   │   │   │   ├── IL1Messenger.sol
│   │   │   │   └── IL2ContractDeployer.sol
│   │   │   └── libraries
│   │   │       ├── DataEncoding.sol
│   │   │       ├── DynamicIncrementalMerkle.sol
│   │   │       ├── FullMerkle.sol
│   │   │       ├── L2ContractHelper.sol
│   │   │       ├── Merkle.sol
│   │   │       ├── MessageHashing.sol
│   │   │       ├── SemVer.sol
│   │   │       ├── SystemContractsCaller.sol
│   │   │       ├── UncheckedMath.sol
│   │   │       └── UnsafeBytes.sol
│   │   ├── governance
│   │   │   ├── AccessControlRestriction.sol
│   │   │   ├── ChainAdmin.sol
│   │   │   ├── Common.sol
│   │   │   ├── IAccessControlRestriction.sol
│   │   │   ├── IChainAdmin.sol
│   │   │   ├── IPermanentRestriction.sol
│   │   │   ├── L2AdminFactory.sol
│   │   │   ├── L2ProxyAdminDeployer.sol
│   │   │   ├── PermanentRestriction.sol
│   │   │   ├── TransitionaryOwner.sol
│   │   ├── state-transition
│   │   │   ├── ChainTypeManager.sol
│   │   │   ├── IChainTypeManager.sol
│   │   │   ├── L1StateTransitionErrors.sol
│   │   │   ├── ValidatorTimelock.sol
│   │   │   ├── Verifier.sol
│   │   │   ├── chain-deps
│   │   │   │   ├── DiamondInit.sol
│   │   │   │   ├── DiamondProxy.sol
│   │   │   │   ├── GatewayCTMDeployer.sol
│   │   │   │   ├── ZKChainStorage.sol
│   │   │   │   └── facets
│   │   │   │       ├── Admin.sol
│   │   │   │       ├── Executor.sol
│   │   │   │       ├── Getters.sol
│   │   │   │       ├── Mailbox.sol
│   │   │   │       └── ZKChainBase.sol
│   │   │   ├── chain-interfaces
│   │   │   │   ├── IAdmin.sol
│   │   │   │   ├── IDiamondInit.sol
│   │   │   │   ├── IExecutor.sol
│   │   │   │   ├── IGetters.sol
│   │   │   │   ├── IL1DAValidator.sol
│   │   │   │   ├── ILegacyGetters.sol
│   │   │   │   ├── IMailbox.sol
│   │   │   │   ├── ITransactionFilterer.sol
│   │   │   │   ├── IVerifier.sol
│   │   │   │   ├── IZKChain.sol
│   │   │   │   └── IZKChainBase.sol
│   │   │   ├── data-availability
│   │   │   │   ├── CalldataDA.sol
│   │   │   │   ├── CalldataDAGateway.sol
│   │   │   │   ├── RelayedSLDAValidator.sol
│   │   │   │   ├── RollupDAManager.sol
│   │   │   │   └── ValidiumL1DAValidator.sol
│   │   │   ├── l2-deps
│   │   │   │   ├── IComplexUpgrader.sol
│   │   │   │   ├── IL2GatewayUpgrade.sol
│   │   │   │   ├── IL2GenesisUpgrade.sol
│   │   │   │   └── ISystemContext.sol
│   │   │   └── libraries
│   │   │       ├── BatchDecoder.sol
│   │   │       ├── Diamond.sol
│   │   │       ├── LibMap.sol
│   │   │       ├── PriorityQueue.sol
│   │   │       ├── PriorityTree.sol
│   │   │       └── TransactionValidator.sol
│   │   ├── transactionFilterer
│   │   │   └── GatewayTransactionFilterer.sol
│   │   ├── upgrades
│   │   │   ├── BaseZkSyncUpgrade.sol
│   │   │   ├── BaseZkSyncUpgradeGenesis.sol
│   │   │   ├── BytecodesSupplier.sol
│   │   │   ├── DefaultUpgrade.sol
│   │   │   ├── GatewayUpgrade.sol
│   │   │   ├── GovernanceUpgradeTimer.sol
│   │   │   ├── IDefaultUpgrade.sol
│   │   │   ├── IGatewayUpgrade.sol
│   │   │   ├── IL1GenesisUpgrade.sol
│   │   │   ├── L1GatewayHelper.sol
│   │   │   ├── L1GenesisUpgrade.sol
│   │   │   └── ZkSyncUpgradeErrors.sol
│   │   └── vendor
│   │       └── AddressAliasHelper.sol
├── l2-contracts
│   ├── contracts
|   |   ├── ConsensusRegistry.sol
|   |   ├── Dependencies.sol
|   |   ├── ForceDeployUpgrader.sol
|   |   ├── L2ContractHelper.sol
|   |   ├── SystemContractsCaller.sol
│   │   ├── data-availability
│   │   │   ├── DAErrors.sol
│   │   │   ├── RollupL2DAValidator.sol
│   │   │   ├── StateDiffL2DAValidator.sol
│   │   │   └── ValidiumL2DAValidator.sol
│   │   ├── errors
│   │   │   └── L2ContractErrors.sol
│   │   ├── interfaces
│   │   │   ├── IConsensusRegistry.sol
│   │   │   ├── IL2DAValidator.sol
│   │   │   ├── IPaymaster.sol
│   │   │   └── IPaymasterFlow.sol
│   │   ├── vendor
│   │   │   └── AddressAliasHelper.sol
│   │   └── verifier
│   │       ├── Verifier.sol
│   │       └── chain-interfaces
│   │           └── IVerifier.sol
├── system-contracts
│   ├── bootloader
│   │   ├── bootloader.yul
│   ├── contracts
|   |   ├── AccountCodeStorage.sol
|   |   ├── BootloaderUtilities.sol
|   |   ├── ComplexUpgrader.sol
|   |   ├── Compressor.sol
|   |   ├── Constants.sol
|   |   ├── ContractDeployer.sol
|   |   ├── Create2Factory.sol
|   |   ├── DefaultAccount.sol
|   |   ├── EmptyContract.sol
|   |   ├── EventWriter.yul
|   |   ├── ImmutableSimulator.sol
|   |   ├── KnownCodesStorage.sol
|   |   ├── L1Messenger.sol
|   |   ├── L2BaseToken.sol
|   |   ├── L2GatewayUpgrade.sol
|   |   ├── L2GatewayUpgradeHelper.sol
|   |   ├── L2GenesisUpgrade.sol
|   |   ├── MsgValueSimulator.sol
|   |   ├── NonceHolder.sol
|   |   ├── PubdataChunkPublisher.sol
|   |   ├── SloadContract.sol
|   |   ├── SystemContext.sol
|   |   ├── SystemContractErrors.sol
|   |   ├── abstract
|   |   │   └── SystemContractBase.sol
|   |   ├── interfaces
|   |   │   ├── IAccount.sol
|   |   │   ├── IAccountCodeStorage.sol
|   |   │   ├── IBaseToken.sol
|   |   │   ├── IBootloaderUtilities.sol
|   |   │   ├── IBridgehub.sol
|   |   │   ├── IComplexUpgrader.sol
|   |   │   ├── ICompressor.sol
|   |   │   ├── IContractDeployer.sol
|   |   │   ├── ICreate2Factory.sol
|   |   │   ├── IImmutableSimulator.sol
|   |   │   ├── IKnownCodesStorage.sol
|   |   │   ├── IL1Messenger.sol
|   |   │   ├── IL2DAValidator.sol
|   |   │   ├── IL2GenesisUpgrade.sol
|   |   │   ├── IL2SharedBridgeLegacy.sol
|   |   │   ├── IL2StandardToken.sol
|   |   │   ├── IL2WrappedBaseToken.sol
|   |   │   ├── IMailbox.sol
|   |   │   ├── IMessageRoot.sol
|   |   │   ├── INonceHolder.sol
|   |   │   ├── IPaymaster.sol
|   |   │   ├── IPaymasterFlow.sol
|   |   │   ├── IPubdataChunkPublisher.sol
|   |   │   ├── ISystemContext.sol
|   |   │   └── ISystemContextDeprecated.sol
|   |   ├── libraries
|   |   │   ├── EfficientCall.sol
|   |   │   ├── RLPEncoder.sol
|   |   │   ├── SystemContractHelper.sol
|   |   │   ├── SystemContractsCaller.sol
|   |   │   ├── TransactionHelper.sol
|   |   │   ├── UnsafeBytesCalldata.sol
|   |   │   └── Utils.sol
|   |   ├── precompiles
|   |   │   ├── CodeOracle.yul
|   |   │   ├── EcAdd.yul
|   |   │   ├── EcMul.yul
|   |   │   ├── EcPairing.yul
|   |   │   ├── Ecrecover.yul
|   |   │   ├── Keccak256.yul
|   |   │   ├── P256Verify.yul
|   |   │   └── SHA256.yul

zk-governance

l1-contracts
├── src
|   ├── EmergencyUpgradeBoard.sol
|   ├── Guardians.sol
|   ├── Multisig.sol
|   ├── ProtocolUpgradeHandler.sol
|   ├── SecurityCouncil.sol
|   ├── TestnetProtocolUpgradeHandler.sol
│   └── interfaces
│       ├── IGuardians.sol
│       ├── IL2Governor.sol
│       ├── IPausable.sol
│       ├── IProtocolUpgradeHandler.sol
│       ├── ISecurityCouncil.sol
│       ├── IChainTypeManager.sol
│       └── IZKsyncEra.sol

l2-contracts
├── src
|   ├── Counter.sol
|   ├── ZkCappedMinter.sol
|   ├── ZkGovOpsGovernor.sol
|   ├── ZkMerkleDistributor.sol
|   ├── ZkProtocolGovernor.sol
|   ├── ZkTokenGovernor.sol
|   ├── ZkTokenV1.sol
|   ├── ZkTokenV2.sol
|   ├── extensions
|   │   ├── GovernorGuardianVeto.sol
|   │   └── GovernorSettableFixedQuorum.sol
|   ├── interfaces
|   │   ├── IMintable.sol
|   │   └── IMintableAndDelegatable.sol
|   └── lib
|       ├── GovernorCountingFractional.sol
|       └── Nonces.sol

Setup

Clone the contest repo:

git clone https://github.com/Cyfrin/2024-10-zksync.git

1. era-contracts/l1-contracts

Build:

yarn && yarn build

Tests:

Foundry:

# Make sure you build all the contracts from the list below to have all the tests working
yarn test:foundry

Hardhat:

yarn test

2. era-contracts/l2-contracts

Build:

yarn && yarn build

Tests:

Hardhat:

# In the first terminal
yarn test-node

# In the second terminal
yarn test

Foundry:

yarn test:foundry

3. era-contracts/system-contracts

Build:

yarn && yarn build

Tests:

# In the first terminal
yarn test-node

# In the second terminal
yarn test

4. era-contracts/da-contracts

Build:

yarn && yarn build && forge compile

5. zk-governance/l1-contracts

Build:

forge build

Tests:

forge test

6. zk-governance/l2-contracts

Build:

forge build

Tests:

forge test

Everything found during previous audits & contests:

• https://docs.zksync.io/build/resources/audit-bug-bounty
• https://code4rena.com/reports/2022-10-zksync
• https://code4rena.com/reports/2023-03-zksync
• https://code4rena.com/reports/2023-10-zksync
• https://code4rena.com/reports/2024-03-zksync

1. Contracts on L1 cannot access their native balance on their aliased L2 address

It is currently not possible for an L1 smart contract to access and transfer the native tokens on their aliased L2 address.

2. Gas spent on pubdata is not subtracted in between near calls, leading to uncompensated operator calculations and potential DOS.

The bootloader executes transactions with the amount of gas that has been requested and paid for by the transactions. Pubdata cost is charged separately from execution cost and must be taken into account by calculating the difference of the pubdata counter after and before the transaction execution and multiplying the result by gasPerPubdata. A transaction is executed over multiple near calls, and so each near call checks if the remaining gas is sufficient to pay for the overall pubdata that the transaction has consumed up to this point. By reverting the near call it is ensured that the overspent gas does not cause any state changes, the operator is forced to perform computations without receiving compensation for it.

3. Validator can provide inefficient bytecode compression

In the current implementation, the mechanism for bytecode compression is not strictly unambiguous. That means the validator has the flexibility to choose a less efficient compression for the bytecode to increase the deployment cost for the end user. Besides that, there is another non-fixed issue, that gives a way for the operator to forces the user to pay more for the bytecode compression or even burn all the transaction gas during bytecode compression verification.

4. extcodehash does not distinguish empty contracts on account balances

According to the EIP-161, an account is “empty” when it meets the following conditions: it has no deployed code, its nonce value is zero, and it holds a balance of zero. According to EIP-1052, the extcodehash of an empty account should evaluate to bytes32(0), otherwice it is keccak256(deployedBytecode). On ZKsync, bytes32(0) is returned in case there is no deployed code and nonce is zero regardless of the account balance.

5. DefaultAccount does not always return successfully

DefaultAccount, while it should always behave as an EOA (i.e. any call to it should return success(0,0)), if called with a selector of one of its methods and incorrect ABI-encoding of its parameters, will fail with empty error. This happens due to the fact that the ABI decoding fails before the modifier is triggered.

6. Fee model may have imperfect price alignment

The price that users pay on L1 may not accurately represent the actual price and may lead to overcharge/undercharge. Also, due to attachment to L1 gas price may incentivize to submit transactions when the L1 gas price is low regardless of the L2 congestion. Generally the fee model may be revised in future releases.