The handleTokenPurchase function contains a vulnerability where it attempts to interact with the staking manager contract without verifying its initialization status. When processing staked purchases (stake = true), the function blindly calls stakingManager.depositByPresale(buyer, amount) without checking if the stakingManager address has been set. Since the staking manager is initialized separately via the setStakingManager function and not in the constructor, transactions will revert if the owner forgets to set this address before processing staked purchases. This creates a potential denial of service condition and wastes gas on failed transactions. To mitigate this, Implement explicit validation by adding a check: require(address(stakingManager) != address(0), "Staking manager not set") at the beginning of the if(stake) block. For enhanced security, also verify the address points to actual contract code with require(address(stakingManager).code.length > 0, "Invalid staking manager").

The setSaleDate function contains a logical flaw by failing to validate that the start date precedes the end date, allowing the owner to create an invalid timeline where endSaleDate < startSaleDate. This inverted relationship breaks core contract functionality by creating a logical impossibility: the sale would never activate since the end condition would be reached before the start condition. This could permanently lock funds in the contract, as token withdrawals require block.timestamp > endSaleDate. Additionally, users would receive contradictory information about sale timing. This vulnerability could be exploited maliciously to prevent token withdrawals indefinitely while maintaining technical contract compliance. To mitigate this issue, implement validation logic that ensures proper chronological order with a simple check: require(startSaleDate < _endSaleDate, "End date must be after start date"). For additional security, add validation against setting dates too far in the past or future to prevent unreasonable sale periods.

The setSaleDate function allows the contract owner to modify both the start and end dates of the presale at any time, including during an active sale. This unrestricted ability creates significant centralization risk and undermines the trustless nature of the contract. The owner could unexpectedly extend the sale to prevent users from withdrawing tokens, suddenly end a sale that was promised to run longer, or continually adjust dates to manipulate market dynamics. Users who participated based on the originally advertised timeline could find themselves locked in a sale with drastically altered terms, with no recourse or protection against these arbitrary changes. Implement restrictions that prevent date modifications once the sale has started or add time locks for changes.

The setToken function contains a vulnerability allowing the owner to change the presale token address at any time, even after users have purchased tokens. This unrestricted ability enables a potential "bait-and-switch" attack where the owner could advertise a valuable token, collect funds, then replace it with a worthless token before users can claim. The function lacks any protective measures: no restrictions based on sale progress, no validation of the new token, no event emission for transparency, and no time locks or multi-signature requirements for such a high-risk operation. This represents an extreme centralization risk that undermines the entire presale's trustworthiness. To mitigate this vulnerability, implement strict safeguards: prevent token changes after sales have begun (require(totalTokensSold == 0)), add zero-address validation, emit events for transparency, and consider implementing a one-time setup mechanism that permanently locks the token address after initial configuration or requires multi-signature approval for changes.

The Presale contract lacks a critical direct buy functionality, forcing token purchases through the owner-controlled handleTokenPurchase function. This design severely violates blockchain's trustless principles by requiring users to complete payments off-chain and trust the owner to manually allocate tokens correctly. This extreme centralization creates significant risks: no on-chain payment verification, no transparent price mechanism, potential for selective allocation, and increased disputes from manual processing. Without direct purchase capability, users must rely entirely on the owner's honesty when attributing token purchases, contradicting the fundamental purpose of smart contracts and creating opportunities for manipulation or favoritism. To mitigate this issue, implement a standard public buy function that accepts ETH or stablecoin payments directly from users, automatically calculates token amounts based on predefined rates, records purchases transparently on-chain, and handles the token allocation without owner intervention. Additional improvements should include rate configuration, purchase limits, and optional whitelist functionality.