Key Takeaways
- Token approvals are onn-chain permissions granted to decentralized protocols, allowing them to access and manage tokens in your wallet.
- They are essential to the functioning of Web3 and DeFi exchange platforms, allowing users to trade crypto assets seamlessly.
- However, some smart contracts contain hidden token approvals, which can leave your wallet vulnerable to malicious transactions.
- Tools like Revoke.cash and Etherscan make it easy to manage token permissions on Ethereum, while Famous Fox Federation offers similar functionality for Solana users.
You woke up to some great news: you sold an NFT you had listed on OpenSea overnight! With no further action from you, the NFT was instantly transferred to the buyer’s wallet, and you received payment to your crypto wallet. The process is seamless – but how was OpenSea able to take a token from your wallet without permission – and should you be worried? The answer lies in something called a token approval.
Token approvals are a component of some smart contracts that allow you to grant decentralized applications – like NFT marketplaces and DeFi protocols – access to your crypto wallet in future. They allow you to buy and sell tokens within limits set by you, without needing a wallet signature for each individual transaction.
Token approvals are essential to the smooth functioning of many Web3 protocols: for example, you can instantly sell an NFT, or execute a “buy” order on a DEX at a certain price. However, they can also be exploited by malicious actors. A seemingly harmless token approval may contain hidden code, enabling hackers to access and drain your wallet in the future.
To protect your assets, revoking your outstanding token approvals is crucial. In this article, we’ll go over some popular tools and show you how to revoke token approvals across different networks.
Revoke Token Approvals on Ethereum Using Revoke.cash
One of the most popular tools to revoke token approvals is Revoke.cash. It offers a user-friendly way to manage and revoke token approvals. By connecting your wallet, you can review all active approvals and take necessary actions. Here’s how to revoke approvals using Revoke.cash:
- Visit Revoke.cash: Navigate to Revoke.cash using a secure browser.
- Connect your wallet: Click the “Connect Wallet” button and choose your preferred wallet. Alternatively, you can simply search for your wallet address.
- Review token approvals: After connecting your wallet/searching, select the blockchain network that you want to check (Ethereum, BNB, etc.). Then, you will see a list of all approved tokens and contracts associated with your account.
- Identify unnecessary approvals: Look for token approvals that are no longer in use or seem suspicious.
- Revoke permissions: Select the token or contract you want to manage, then click “Revoke” to remove its access. Confirm the transaction through your wallet.
How To Revoke Token Approvals Using Etherscan
Etherscan is probably the most popular Ethereum blockchain explorer and it provides another method to manage and revoke token approvals. The platform has a beta feature that functions in a way similar to Revoke.cash. Here’s how to revoke approvals using Etherscan:
- Visit Etherscan: Go to Etherscan.
- Select Token Approvals: Next, hover over the “More” section and select “Token Approvals”.
- Search Your Address: Then you can enter your wallet address in the search bar to check any permissions.
- Connect your wallet: If you want to manage any permissions, connect your wallet by clicking the “Connect to Web3” button.
- Revoke unwanted approvals: Select the tokens or contracts you wish to revoke, then click “Revoke.” Finally, confirm the action in your wallet to complete the process.
Revoke Token Approvals on Solana Using Famous Fox
Solana’s market share continues to grow and the network has become home to a significant portion of the crypto token ecosystem. Consequently, many users interact with token approvals on Solana. Furthermore, with many of them being memecoins, the risks of signing a malicious smart contract are as high as ever.
If you’re looking for a way to revoke token approvals on Solana, the Famous Fox Federation offers an intuitive tool for managing them:
- Access Famous Fox Federation: Go to Famous Fox Federation and navigate to their utility section.
- Select the Revoker: Then, find the Revoker tool and click on it.
- Connect your wallet: Click “Connect Wallet” and select your Solana-compatible wallet, such as Phantom.
- View active approvals: Then, review the list of token approvals associated with your wallet.
- Revoke approvals: Finally, identify permissions you no longer need, then click “Revoke” to remove them. Confirm the transaction in your wallet.
By managing token approvals on Solana, you can protect your assets and ensure your wallet remains secure.
Why It’s Important To Remove Token Approvals
Failing to revoke token approvals can leave your wallet vulnerable to potential scams and malicious attacks. In addition, as we’ll see with an example further down, the negative results of attacks don’t always happen right away. Here are some key reasons why managing these permissions is critical:
- Crypto phishing scams: Hackers often deploy sophisticated phishing scams using smart contracts. Consequently, an approval you signed unknowingly could give attackers access to your funds at a later point.
- Complexity of smart contracts: Many users don’t fully understand how smart contracts work, thus making it easier for malicious actors to exploit this knowledge gap.
- Indefinite approvals: Once granted, token approvals can remain active indefinitely. This means a malicious contract can strike at any time unless revoked.
Token Approval Scam Examples
Token approval scams are an ongoing issue in the crypto space as hackers constantly find new ways to exploit unsuspecting users. As a result, it’s always worth keeping up with the latest threats in the space. Below are two notable examples of these scams:
Fake Token Approvals on OpenSea
A few years ago, a scam targeting OpenSea users involved fake token approvals. Hackers sent users phishing emails urging them to click a link and approve a token transfer. Those who fell for the scam unknowingly granted access to their NFTs, which were then stolen.
10 BTC Lost to Phishing Attacks
In a more recent example, attackers executed a phishing attack and stole 10 BTC but the interesting part is that it happened two years after the initial attack. X user “Anchor Drops” reported losing 10 BTC and over $1.5 million in NFTs after the assets disappeared from his Ledger hardware wallet.
After checking his signed transactions on an explorer it came to light that Anchor Drops signed a malicious transaction back in 2022. This shows that phishing attacks are not always instant but remain just as dangerous.
Closing Thoughts
In conclusion, revoking token approvals is a fundamental practice for maintaining the security of your crypto wallet. With tools like Revoke.cash, Etherscan, and Famous Fox Federation, you can easily manage your permissions and minimize risks associated with malicious smart contracts.
