The contract lacks a validation check to ensure that specific parameters are contract addresses. Without this check, there is a risk that non-contract addresses (such as externally owned accounts, or EOAs) could be mistakenly set for parameters intended to reference other contracts. This could lead to failures in executing critical interactions within the contract, as EOAs do not support contract-specific functions.

The updateRefferPercentage function allows the owner to set any arbitrary value for the referral percentage without validation constraints. This is especially concerning as the refferPercentage value directly impacts token distribution calculations in the buy functions where it's used to calculate referral rewards (_referAmount = (_amount.mul(refferPercentage)).div(10000)). Without bounds checks, the owner could potentially set this value excessively high (e.g., >10000), resulting in referral rewards that exceed the principal investment amount, or set it to zero, eliminating referral incentives entirely.

The buy function erroneously stores payment amounts (USDT/WETH) in vestedBalance mapping instead of token amounts, creating a fundamental mismatch between purchased tokens and vested tokens. Since the claim function uses vestedBalance values to calculate token distributions, users will receive significantly fewer tokens than they purchased (e.g., if 100 USDT buys 1000 tokens, users would only receive 100 tokens through vesting). This critical issue undermines the entire vesting mechanism and would result in substantial financial loss for participants.

The buyWithBNB function calculates token amounts based on current BNB/token exchange rates at transaction execution time without allowing users to specify a minimum acceptable amount. This creates significant risk during volatile market conditions or high network congestion, where users might receive far fewer tokens than expected when their transaction executes. Without slippage protection, users have no guarantee about the minimum tokens they'll receive for their BNB, potentially resulting in unfavorable executions that still succeed rather than reverting when prices move against them.

The claim function only performs basic timing checks (saleEndTime > 0 and block.timestamp >= saleEndTime) to determine if tokens can be claimed, but lacks comprehensive verification that the vesting schedule has been properly initialized and configured. Without validating that all vesting parameters are properly set, there's a risk that claims could begin prematurely or with incorrect parameters. This is particularly concerning given that the vestedPeriod is set to a testing value of 5 minutes and there's no explicit function to properly initialize the vesting schedule when transitioning from the sale to vesting phase.