Root + Impact

Description

• in the enterRaffle() method, there is a duplicates check for input param address[], using a loop-through the array.

• due to solidity version 0.7.6, and the implementation of the loop, mentioned below, passing an empty array would underflow the players.length to = 2^256-1 thus forcing an infinite loop which would spend all the gas and revert the transaction.

  for (uint256 i = 0; i < players.length - 1; i++)

Risk

Likelihood:

• As per the implementation, the enterRaffle() method has public visibility and anyone could pass the empty array, even without spending any ETH, as the method calculates the fee based on the array length. Calls to the method are not restricted by anything

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Impact:

• Calls with an empty array would lead to gas griefing, rendering a base functionality of the protocol unusable.

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Proof of Concept

Recommended Mitigation