Summary:

modifier needs to be redesigned with gas efficiency and security in mind. it will fail for big number of beneficiaries, say 200, which may exceed block gas limits.

Vulnerability Details

1. DOS Vulnerability: An owner could intentionally or unintentionally add so many beneficiaries that certain functions become unusable due to gas limits.

2. Poor Design Pattern: Using array iteration that could reach out-of-bounds is an inherently risky pattern.

3. Scalability Issue: The contract doesn't handle a scenario with many beneficiaries efficiently.

Impact

1. For very large beneficiary arrays, transactions will fail with "out of gas" errors

2. Linear or worse growth in gas consumption as the array size increases

3. Concrete gas usage numbers that can be compared against block gas limits

Tools Used

Recommendations

redesign and replace the loop