Summary

Incorrect duplicate address check

Vulnerability Details

In ARE_LISTS_VALID(), the inner loop starts from 1 and not zero. What this means is that if there is a duplicate address as the first element and consequently at third or fourth element, the function won't revert.

This is because the first inner element is skipped.

Impact

Possibility of existence of duplicate address.

Tools Used

Manual review

Recommendations

The inner loop should start from 0 instead of 1.