Tadle

Github

• https://github.com/Cyfrin/2024-08-tadle/blob/04fd8634701697184a3f3a5558b41c109866e5f8/src/core/CapitalPool.sol#L24

Summary

The approve function in the CapitalPool contract does not emit an event after a successful token approval. This omission hinders the ability to monitor and audit contract actions off-chain, reducing transparency and making it difficult to trace approvals, which are critical operations in a decentralized environment.

Vulnerability Details

In Solidity, events are crucial for logging significant actions performed by contracts. They allow off-chain tools, such as block explorers and monitoring systems, to track and record specific activities. In the context of the approve function, the absence of an event means that there is no record of when a token approval occurs, which can obscure the contract's operation and make it harder to detect potential issues or misuse.

The current approve function is designed to approve an unlimited amount of tokens for the tokenManager but does not notify the network of this action by emitting an event. As a result, it becomes challenging to track when, by whom, and for which tokens approvals were granted.

Impact

Without event logs, off-chain monitoring tools cannot track when and where approvals are made. This lack of transparency can make it difficult to audit the contract and detect unauthorized or suspicious activity. In the event of a security incident or bug, the absence of event logs makes it harder to reconstruct the sequence of actions that led to the issue. This can delay incident response and remediation.

Tools Used

Manual Review

Recommendations

Add an event definition at the contract level that logs the details of each approval. This event should include relevant information such as the token address, the tokenManager address, and the approved amount.