Beanstalk Part 2

Summary

See below...

Vulnerability Details

The claimFertilized function interacts with external contracts and performs token transfers. Although it doesn't directly expose sensitive state changes before the external calls, it's susceptible to reentrancy attacks if any of the external contracts or the LibTransfer library contains functions that can call back into the contract being executed. Let's examine the code snippet:

This function is responsible for allowing users to claim fertilized tokens. It interacts with the C.fertilizer() and C.bean() contracts to update balances and transfer tokens, respectively. However, if any of these external contracts implement functions that can trigger callbacks to the claimFertilized function while it's in an inconsistent state, a reentrancy attack can occur. This could potentially lead to unexpected behavior and loss of funds.

Impact

The impact of a successful recursive call in the claimFertilized function could result in unauthorized transfers of tokens, manipulation of balances, and potentially financial losses for affected users.

Tools Used

Manual

Recommendations

Follow the "Checks-Effects-Interactions" pattern, where state changes are made before interacting with external contracts.