Zaros Part 1

Summary

The createTradingAccountAndMulticall function in the TradingAccountBranch contract is vulnerable to reentrancy attacks due to insufficient validation of the data payload. This vulnerability allows attackers to exploit reentrancy opportunities and manipulate contract state or access functions unauthorizedly.

Vulnerability Details

The createTradingAccountAndMulticall function allows users to create a new trading account and execute multiple calls within a single transaction. However, the function does not adequately validate the data payload, enabling reentrancy attacks. Attackers can exploit this by crafting malicious payloads that call back into the vulnerable function, causing unexpected behaviors or unauthorized state changes.

Impact

The impact of this vulnerability is significant as it could lead to the following issues:

• Unauthorized access to contract functions

• Manipulation of contract state

• Potential financial loss due to reentrancy attacks

Tools Used

• Manual code review

• LLM

Recommendations

1. Validate Payload Data: Ensure that the data payload is thoroughly validated before execution to prevent malicious input from causing unintended behaviors.

2. Ensure State Changes Before External Calls: Make sure that all critical state changes are performed before any external calls.

3. Implement Access Control Mechanisms: Use access control checks to ensure that only authorized entities can call sensitive functions.

   
   
   Example Fix:

   function createTradingAccountAndMulticall(

   bytes[] calldata data,

   bytes memory referralCode,

   bool isCustomReferralCode

   )

   external

   payable

   virtual

   returns (bytes[] memory results)

   {

   // Ensure state changes before any external calls

   uint128 tradingAccountId = createTradingAccount(referralCode, isCustomReferralCode);

   ​

   // Initialize results array

   results = new bytes[](data.length);

   ​

   // Iterate through data array and validate each call

   for (uint256 i; i < data.length; i++) {

   // Validate function selector

   bytes4 selector = bytes4(data[i][:4]);

   require(isValidFunctionSelector(selector), "Invalid function selector");

   ​

   // Concatenate the tradingAccountId with the function call data

   bytes memory dataWithAccountId = bytes.concat(data[i][0:4], abi.encode(tradingAccountId), data[i][4:]);

   ​

   // Make external call

   (bool success, bytes memory result) = address(this).delegatecall(dataWithAccountId);

   ​

   // Handle failure

   if (!success) {

   uint256 len = result.length;

   assembly {

   revert(add(result, 0x20), len)

   }

   }

   ​

   // Store result

   results[i] = result;

   }

   }

   ​

   // Helper function to validate function selectors

   function isValidFunctionSelector(bytes4 selector) internal pure returns (bool) {

   return (

   selector == this.someFunction.selector ||

   selector == this.anotherFunction.selector ||

   // Add more valid function selectors as needed

   false

   );

   }

   ​