Inability to withdraw funds for certain users due to `whenNotPaused` modifier in `RateLimitedMinter`

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Lines of code

https://github.com/code-423n4/2023-12-ethereumcreditguild/blob/main/src/rate-limits/RateLimitedMinter.sol#L52

Vulnerability details

med

Impact

From the contest documentation:

[The GUARDIAN role] is expected to be able to freeze new usage of the protocol, but not prevent users from withdrawing their funds.

However, due to the whenNotPaused modifier in the RateLimitedMinter.mint() function, users who have CREDIT tokens staked on a gauge with a pending guildReward will not be able to withdraw their funds. This is because the SurplusGuildMinter.unstake() function attempts to mint rewards through the RateLimitedMinter in the getRewards() function prior to unstaking. If the protocol is paused, this step will fail, causing the transaction to revert and preventing users from withdrawing their funds.

Proof of Concept

Consider a scenario where Alice has CREDIT tokens staked on a gauge with a pending guildReward. Then, the protocol is paused and Alice attempts to unstake her tokens by calling the SurplusGuildMinter.unstake() function, which in turn calls the getRewards() function. This function attempts to mint rewards through the RateLimitedMinter.mint() function. However, because the protocol is paused, this function cannot be executed, causing the transaction to revert and preventing Alice from unstaking and withdrawing her funds.

https://github.com/code-423n4/2023-12-ethereumcreditguild/blob/main/src/rate-limits/RateLimitedMinter.sol#L52 https://github.com/code-423n4/2023-12-ethereumcreditguild/blob/main/src/loan/SurplusGuildMinter.sol#L158-L163 https://github.com/code-423n4/2023-12-ethereumcreditguild/blob/main/src/loan/SurplusGuildMinter.sol#L259

Tools Used

Manual review

Recommended Mitigation Steps

Provide an emergencyWithdraw method allowing users to withdraw their funds while foregoing rewards when the protocol is paused. This change should be carefully reviewed and tested to ensure it does not introduce other security risks.