When we interact with a DeFi protocol, an NFT marketplace, or a decentralized exchange (DEX), we almost always need to sign an “Approve” or “Permit” transaction. This authorization gives the contract the right to spend a specific token (or an unlimited amount of it) on our behalf. The problem is that once the transaction is complete, the contract still has permission unless we explicitly revoke it.
Why are open contract approvals a real danger?
Protocol compromise (exploits): If a legitimate protocol you interacted with in the past is hacked and its code or front end is compromised, hackers can exploit all the old approvals users left active to drain their wallets. How can you protect yourself and manage these permissions?
Good security practice requires periodically revoking unused approvals. To do this, we use specialized permission auditing tools that check which addresses have access to your tokens.
The main trusted tools for this cleanup are:
Revoke.cash (One of the most popular and trusted tools on the market)
Etherscan / BscScan / Polygonscan Token Approvals (Native tools provided by the block explorers themselves for Ethereum, BNB Chain, Polygon, etc.)
DeFiLlama Approvals
Basic steps for revoking approvals:
Visit a trusted tool such as Revoke.cash.
Connect your wallet (make sure to connect for read-only viewing only; never sign anything suspicious when connecting).
Select the desired network (Ethereum, Arbitrum, Polygon, etc.).
Check the list of approved contracts and the limits granted (many are shown as "Unlimited").
Click Revoke to end the approval. A small network gas fee will be charged to process the revocation.
Making this cleanup a habit after one-off transactions—especially on high-risk networks or with new protocols—is an essential layer of protection for safeguarding your assets in the long term.
