When you click "Connect DApp" in your Binance Web3 wallet, the two words you need to watch most in the pop-up are "amount" and "unlimited". Unlimited approval means you give someone full control over a certain asset in your wallet all at once. If that project later has a problem, that token in your account can be emptied directly.
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Step 1: Find the two most important details in the approval pop-up
When you connect to a DApp or start a transaction in your Binance wallet, the approval pop-up usually shows the following. Read them before clicking "Confirm":
Amount (Spending Cap / Allowance Amount): If it shows a specific number like "0.1 BNB" or "1,000 USDT", the approval has a limit. If it shows "Unlimited" or a symbol like "2^256-1", the other side can call your full balance of that token again and again until you manually revoke it.
Receiving Contract Address (Contract Address / Spender): Check whether this address matches the official address published by the project. If it does not match, it is likely a phishing site or malicious contract. If you approve it, your assets may be moved out.
Common reason for failure: Many people click "Confirm" out of habit without noticing that the amount field says "Unlimited". They only realize it after their assets are moved out.
Step 2: How risky is unlimited approval?
Two real examples make it clear:
MEV bot lost $7.5 million: The attacker first made the target wallet keep large unlimited approvals, then used the transferFrom function to call 66 fake contracts in batches and moved out the assets that had already been approved. This bot was not an ordinary user; it was a professional player that made money from front-running transactions. Even it did not defend against the attack.
LI.FI protocol upgrade vulnerability: A vulnerability appeared during a smart contract upgrade. The attacker used the unlimited approvals users had previously given to the LI.FI contract to take funds directly from those wallets. Users did not need to confirm any new action.
Core logic: Unlimited approval is like giving someone a "master key". The key does not expire just because you do not use it today. It stays on-chain. If the project is attacked, runs away, or its contract is tampered with later, your assets are directly exposed. In early 2024, more than $55 million in assets were stolen in a single month because of this type of approval.
Step 3: Two habits to reduce risk
Choose "custom amount" when approving: If the DApp allows it, do not choose "Unlimited". Manually enter the specific amount needed for this transaction. Binance is also limiting unlimited approvals on some chains to improve security.
Revoke when you are done: Regularly clean up approvals you no longer use. In the Binance Web3 wallet, go to [Settings] → [Security Center] → [Security Scan]. The system will automatically check your approval status and supports one-click revocation when high-risk approvals are found.
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How to check after the operation is complete
After revoking an approval, switch back to the assets page and refresh your balance. If the balance has not changed, the revocation was successful and no funds were lost because of the revoke action.
