Replay Attack Exercise 2

Intro

Realty is a fractional and frictionless real estate investing platform. For the first time, investors from around the world can purchase real estate through fully-complimentary, fractional, tokenized ownership. Powered by blockchain.

The RealtyToken.sol is an ERC721 token which represents shares in a real estate assets.

The maximum number of shares for an asset is 100 (each share represents 1% of the assets).

Investors can purchase shares through the RealtySale.sol contract, every share cost 1 ETH.

A custom share price mechanism exists as well (based on a price oracle), which may be used by the project admin to allow shares to be purchased at a discounted price in certain market conditions.

You've always been interested in real estate investing, and now you can participate in on-chain real estate tokenized investments. But you're broke, and you only have 1 ETH.

Can you buy all the shares with 1 ETH?

Accounts

• 0 - Deployer & Signer 1
• 1 - User1
• 2 - User2
• 3 - Attacker (You)

Tasks

Task 1

Purchase all the available shares of the real estate asset (RealtyToken.sol).

Task 2

Make sure that the Smart Contract RealtySale.sol is secured in order to prevent any exploits from taking place.