First Flight #1: PasswordStore

Summary

The PasswordStore smart contract, which is designed to store a user's private password, has a critical vulnerability. The s_password and s_owner variables, which are marked as private, can be read by anyone directly from the contract's memory data.

Vulnerability Details

In Solidity, the private access specifier only restricts other contracts from accessing a variable, but it doesn't encrypt or hide the variable's value from the Ethereum state. Consequently, any Ethereum user or node can read this information directly from the Ethereum state data.

For the PasswordStore contract:

• s_password: Stores the user's password.

• s_owner: Stores the address of the owner of the contract.

Both of these critical pieces of data are exposed, making them visible to anyone who queries the contract's state.

Impact

Any malicious actor or curious individual can easily obtain the password and the owner's address. This defeats the purpose of the contract, which is to keep the password private. It compromises the integrity and security of the users who rely on this contract.

Tools Used

No specialized tools are needed. The Ethereum state can be queried using standard Ethereum libraries like web3.js, ethers.js, or even by directly accessing an Ethereum node.
Here is another interesting online tool evm.storage

Recommendations

1. Consider not storing sensitive data, like passwords, directly on the blockchain due to its transparent nature. If necessary, use cryptographic methods like hashing or encryption before storing.

2. Educate users about the transparent nature of blockchain and its implications on privacy.