In response to THORChain’s treasury report for Q1 2022 launched on April 1, the chain registered a progress in income regardless of the twofold influence of persistent market sluggishness and extremely unstable geopolitical components. Public information reveals that THORChain recorded $2.17 billion in income in Q1 2022. THORChain, acclaimed because the “cross-chain model of UniSwap”, gained a foothold within the cross-chain buying and selling market counting on its distinctive benefits and earned intensive recognition amongst traders.
Behind all these glamours, THORChain can also be deeply troubled by hacking. The chain suffered frequent safety breaches because it was launched on Ethereum, a indisputable fact that casts doubt on its safety. On April 11, THORChain tweeted about phishing assaults, warning customers to not work together with [DeTHOR] or different unknown tokens inside their wallets, which as soon as once more raised considerations about its safety points.
Whereas constructing a sound safety system for CoinEx merchandise, the CoinEx safety staff additionally retains monitor of safety incidents within the blockchain house to assist customers higher perceive the safety of various initiatives from the angle of technical safety and mitigate the funding danger. Aiming to enhance the safety standards for the blockchain sector, the CoinEx safety staff has analyzed the safety dangers of THORChain (RUNE). The staff hopes that THORChain may be aware and mitigate the next dangers by optimizing the related good contract codes. As well as, this text can also be a warning for customers, reminding them to be extra conscious of asset safety and keep away from asset losses.
How safe is THORChain (RUNE)?
By way of evaluation of the contract code and logic of THORChain (RUNE), the CoinEx safety staff has discovered the next dangers:
To start with, let’s take a look at the contract code of THORChain (RUNE):
https://etherscan.io/address/0x3155ba85d5f96b2d030a4966af206230e46849cb#code
We are able to inform that RUNE is a fairly normal ERC-20 token. It must be famous that aside from the ERC-20 interface, THORChain (RUNE) affords a further interface:
In response to transferTo (as proven within the image above), THORChain (RUNE) makes use of tx.origin, which is among the causes behind its safety dangers. Right here, we should always clarify the distinction between tx.origin and msg.sender:
The under image describes what occurs when an everyday deal with calls the good contract:
In such instances, msg.sender = account.deal with, and tx.origin = account.deal with, which implies that msg.sender is simply the identical as tx.origin.
The next is what occurs when an account calls contract A, and contract A calls contract B:
When contract A calls contract B (as proven above), we will inform that msg.sender equals tx.origin in contract A.
Nevertheless, in contract B, msg.sender = contractA.deal with, whereas tx.origin = account.deal with. Due to this fact, tx.origin is sort of a world variable that traverses your complete name stack and returns the deal with of the account that initially despatched the transaction. That is the important thing difficulty: thus far, virtually all identified assaults in opposition to THORChain (RUNE) relate to tx.origin.
Let’s now learn how attackers steal customers’ RUNE tokens by tx.origin:
Assault No.1: Pilfer a Goat from a Herd
Addresses on Ethereum are divided into exterior addresses and contract addresses. Transferring ETH to those two forms of addresses by exterior addresses is essentially totally different. The Official Documentation of solidity states {that a} contract deal with should implement a obtain Ether operate earlier than making transfers.
In mild of the options of tx.origin, hackers could construct an Assault contract:
When the Assault contract receives an ETH switch from a consumer, it is going to “pilfer a goat from a herd” — the contract will steal the consumer’s RUNE tokens within the course of.
Assault No.2: Inner Assault
An Inner Assault is a particular sort of assault. When attempting to steal a consumer’s RUNE by an Inner Assault, the hacker must have a medium token. Furthermore, the token should additionally name third-party contracts. In response to the switch information of RUNE on Ethereum, some attackers hacked RUNE by AMP Token transfers.
AMP Token makes use of the ERC-1820 normal to handle Hook registration and study whether or not Hook is registered upon every switch. If Hook has been registered, then the Hook shall be known as.
The contract code of AMP Token reveals that the ultimate implementation of the switch is: _transferByPartition. In the meantime, there are two calls involving transferHook: _callPreTransferHooks (earlier than the switch) and _callPostTransferHooks (after the switch). Particularly, _callPreTransferHooks is for the from deal with, whereas _callPostTransferHooks is for the to handle (i.e. the receiving deal with).
For normal customers, stealing tokens from themselves is pointless. Due to this fact, attackers could exploit _callPostTransferHooks. Let’s now take a look at the codes of _callPostTransferHooks.
IAmpTokensRecipient(recipientImplementation).tokensReceived()
We are able to inform that the one callback that attackers may exploit is IAmpTokensRecipient(recipientImplementation).tokensReceived()
Subsequent, we are going to illustrate how this name can be utilized to switch a consumer’s RUNE whereas making an AMP Token switch.
Step 1: A name contract is required (as proven under):
Step 2: Deploy the contract to acquire the Assault Handle.
Step 3: Name the ERC-1820 contract interface (setInterfaceImplementer) to register the interface.
ERC-1820 Handle: 0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24
Contract interface: setInterfaceImplementer(deal with toAddr, bytes32 interfaceHash, deal with implementer)
Particularly, toAddr is the receiving deal with of the AMP switch,
interfaceHash为AmpTokensRecipient的hash:
0xfa352d6368bbc643bcf9d528ffaba5dd3e826137bc42f935045c6c227bd4c72a
interfaceHash is the hash of AmpTokensRecipient:
0xfa352d6368bbc643bcf9d528ffaba5dd3e826137bc42f935045c6c227bd4c72a
Implementer is the Assault Handle obtained in Step 2.
Step 4: Lure a consumer to switch AMP to the toAddr to set off a callback, and steal his RUNE on the similar time.
Assault No.3: Phishing Assault
As its identify suggests, in a phishing assault, the attacker guarantees to present away unimaginable advantages to lure customers into performing sure contract operations. Right here, we are going to introduce a standard phishing assault.
Step 1: The attacker points an ERC-20 token, and will write it into any contract interface that entails signatures.
Step 2: Create a buying and selling pair on Uniswap or every other swap;
Step 3: Supply airdrops to all customers/addresses who maintain RUNE tokens;
The preliminary work of the phishing assault is mainly accomplished by the above these steps. Subsequent, the attacker solely has to attend for customers to commerce on a swap, and customers danger shedding their RUNE as soon as they carry out operations corresponding to approve, switch, and so forth.
As well as, to be able to additional confirm the safety danger of THORChain contract code, CoinEx has mentioned with the safety staff from SlowMist and PeckShield, two well-known safety companies within the business. Confirmed by SlowMist and PeckShield, the safety danger talked about above does exist.
To date, we’ve lined a number of forms of assaults, in addition to the safety dangers that customers are uncovered to.
How ought to the challenge staff optimize the contract code to make itself safer and shield customers’ property?
The one reply is to be cautious about utilizing tx.origin.
How can common customers mitigate dangers and shield their property within the face of assaults that appear unavoidable? The CoinEx safety staff affords the next solutions:
- For Assault No.1: When making a switch, preserve monitor of the estimated Gasoline consumption. For an everyday ETH switch, a Gasoline charge of 21,000 is greater than sufficient. Watch out if the Gasoline consumption far exceeds that determine.
- For Assault No.2: Isolate your tokens by adopting totally different wallets. You’ll be able to retailer totally different tokens in numerous addresses. Additional warning is required with regards to the recent pockets deal with supplied by exchanges.
- For Assault No.3: Greed is the supply of all evil. Don’t blindly take part in any airdrop occasion.
Safety has all the time been a prime concern within the blockchain sector. All gamers, together with challenge groups and exchanges, ought to prioritize safety throughout challenge operation, preserve customers’ property secure and safe, and collectively promote the sound progress of the blockchain business.
