First Flight #1: PasswordStore

Summary

The PasswordStore contract within the provided codebase is intended to securely hold a password for the contract owner. However, due to the transparent nature of blockchain technology, the private visibility specifier doesn't provide the expected level of data privacy. Despite the restrictions placed within the contract's functions, the value of the password stored in the s_password variable is publicly visible to anyone inspecting the blockchain's state.

Vulnerability Details

The contract utilizes a private variable s_password to store a password and restricts access to this password through the getPassword function, only allowing the contract owner to retrieve it. However, this mechanism is flawed due to the transparent nature of blockchain data. All data, including that marked as private, is visible to any party with access to the blockchain's state data. Additionally, the setPassword function emits an event SetNetPassword whenever the password is changed, which, while not leaking the password itself, could leak the timing of password changes.

Code Snippet:

Impact

The impact of this vulnerability is high. The contract owner's password is exposed to the public, leading to a complete loss of confidentiality. This exposure could potentially lead to unauthorized access or other malicious activities if the password is reused elsewhere.

Tools Used

• Manual Code Review

Recommendations

• It is highly advised not to store sensitive information such as passwords on-chain. Blockchain's transparency makes it unsuitable for holding confidential data.

• If authentication is necessary, consider implementing off-chain solutions or using cryptographic proofs, like signatures, to verify identities.

• Replace the password storage and retrieval system with a more secure, off-chain solution to ensure the confidentiality and integrity of sensitive data.