Summary

The current implementation of the setUpdateWeightRunnerAddress allows admin to set the old address (the current value of updateWeightRunner) as the new _updateWeightRunner address, which could remain unchanged since the admin is setting the same value.

Vulnerability Details

If the admin set in the same address as before the system will remain unchanged, this effectively becomes a no-op functionality, as the system behavior remains the same.
The function event will definitely be emitted, but it will log the same address for both the old and new values. This might cause confusion i.e. if logs are being reviewed because it appears as though an update occurred, even though the address didn't change.
Meanwhile the transaction will still consume gas unnecessarily, even though no actual state change occurs.

Impact

Potential misuse: Where by admin might mistakenly think they needed to reset the address.
Gas consumption: Since no actual state changes.
Confusion when event are emitted but log the same address if being reviewed.

Tools Used

Manual review

Recommendations

To prevent this, the function should include a check to ensure the new address is different from the current one