Storage Proofs

Summary

In the update_profit_max_unlock_time function of ScrvusdOracleV2.vy, the variable self.last_update is not updated with the latest block timestamp. This inconsistency may affect functions that rely on self.last_update for time-dependent calculations, potentially leading to incorrect price updates or profit unlock mechanisms.

Vulnerability details

• The function update_profit_max_unlock_time is responsible for updating the profit_max_unlock_time value.

• It performs an access control check and ensures that _block_number is valid.

• However, unlike the update_price function, which updates self.last_update, this function fails to do so.

• self.last_update is used in various calculations, particularly in _smoothed_price, which influences price updates and unlocking mechanisms.

• As a result, any logic dependent on self.last_update may operate on outdated timestamps, leading to unexpected behavior.

Impact

• Incorrect Unlock Time Calculation: The lack of self.last_update updates could result in stale timestamp values, affecting the smooth unlocking of profits.

• Potential Exploit Opportunity: Attackers may leverage this issue to manipulate the unlocking mechanism, causing unintended delays or accelerating profit unlocking inconsistently.

• Inconsistent State Updates: Other functions relying on self.last_update for time-based calculations may not reflect the correct time progression, leading to inaccurate price or supply values.

Recommendation

• Ensure that self.last_update is updated to block.timestamp in the update_profit_max_unlock_time function, similar to how it's handled in update_price.

• Modify the function as follows:

  @external

  def update_profit_max_unlock_time(_profit_max_unlock_time: uint256, _block_number: uint256) -> bool:

  access_control._check_role(UNLOCK_TIME_VERIFIER, msg.sender)

  assert self.last_block_number <= _block_number, "Outdated"

  self.last_block_number = _block_number

  prev_value: uint256 = self.profit_max_unlock_time

  self.profit_max_unlock_time = _profit_max_unlock_time

  # Fix: Update self.last_update to current timestamp

  ++ self.last_update = block.timestamp

  ​

  return prev_value != _profit_max_unlock_time

  ​