Lack of indexed event parameters will affect offchain monitoring

[code423n4]

Handle

0xRajeev

Vulnerability details

Impact

Indexed event parameters are stored in the topics part of the log instead of the data part, which allows for faster indexing/querying because of the use of bloom filters for topics. Up to three parameters in every event can be indexed. While this costs a little extra gas, doing so allows for faster and more efficient/effective event lookups.

While this is used in some events, there are many that are missing indexed keywords for address parameters that could use them.

Proof of Concept

https://github.com/code-423n4/2021-09-defiProtocol/blob/52b74824c42acbcd64248f68c40128fe3a82caf6/contracts/contracts/interfaces/IAuction.sol#L40-L44

https://github.com/code-423n4/2021-09-defiProtocol/blob/52b74824c42acbcd64248f68c40128fe3a82caf6/contracts/contracts/interfaces/IBasket.sol#L47-L48

Tools Used

Manual Analysis

Recommended Mitigation Steps

Add indexed parameter especially for address parameters where their faster lookup for security monitoring issues can be a good trade-off for the extra gas consumed.

[frank-beard]

not an exploit

[GalloDaSballo]

Non critical