First Flight #2: Puppy Raffle

Summary

The refund() function in the PuppyRaffle contract does not check the return value of the sendValue() function. This means that it is possible for the sendValue() function to fail and the contract to still set the player's address to address(0).

Vulnerability Details

The refund() function sends the player's entrance fee back to the player using the sendValue() function. The sendValue() function returns a boolean value indicating whether the transfer was successful. However, the refund() function does not check the return value of the sendValue() function. This means that it is possible for the sendValue() function to fail and the contract to still set the player's address to address(0).

Impact

The contract may not respond to or account for cases where the transfer fails, such as due to out-of-gas errors or an invalid destination address. This can result in Ether being stuck or unaccounted for, potentially affecting the contract's functionality and user experience.

Tools Used

Manual analysis

Recommendations

The refund() function should check the return value of the sendValue() function and revert the transaction if the transfer fails