Cyfrin / 2023-08-sparkn

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Establishes ProxyFactory for contest management, but has unresolved security vulnerabilities requiring attention. #866

Closed codehawks-bot closed 1 year ago

codehawks-bot commented 1 year ago

Establishes ProxyFactory for contest management, but has unresolved security vulnerabilities requiring attention.

Severity

Medium Risk

Summary

The provided code is for a contract called ProxyFactory, which serves as the main entry point for users to deploy proxy contracts and manage contests in the SPARKN ecosystem. The contract allows users to create proxy contracts for contests and distribute prizes to winners. The code appears to handle contest registration, deployment of proxy contracts, and prize distribution through various methods. However, there are some security vulnerabilities and issues present that need to be addressed.

Vulnerability Details

  1. Potential Reentrancy Vulnerability: The _distribute function uses a delegate call to execute the prize distribution logic on the proxy contract. Delegate calls can be exploited for reentrancy attacks if not properly managed. An attacker could manipulate the prize distribution logic to reenter the contract and potentially disrupt the distribution process.

  2. Lack of Input Validation in Signature Verification: The deployProxyAndDistributeBySignature function verifies the organizer's signature without validating the inputs (contest ID and data). This could lead to unintended behavior if malicious inputs are used to create proxy contracts.

  3. Inadequate Signature Verification: The signature verification in the deployProxyAndDistributeBySignature function uses ECDSA.recover, which can return address(0) if the signature is invalid. However, the code only checks if the recovered address matches the organizer's address. This can lead to an incorrect execution flow if ECDSA.recover returns address(0) for a valid signature.

  4. Integer Overflow: The loop in the constructor (for (uint256 i; i < _whitelistedTokens.length;)) lacks a condition to prevent integer overflow, potentially causing unexpected behavior.

Impact

These vulnerabilities could have severe consequences for the security and integrity of the contract and its users:

Tools Used

The vulnerabilities were identified through manual code analysis by security experts.

Recommendations

  1. Reentrancy Protection: Implement a reentrancy guard in the _distribute function to prevent potential reentrancy attacks during prize distribution.

  2. Input Validation in Signature Verification: Validate the inputs (contest ID and data) before proceeding with signature verification in the deployProxyAndDistributeBySignature function.

  3. Improved Signature Verification: Instead of relying solely on matching the recovered address to the organizer's address, implement a robust signature verification process that ensures the validity of the signature.

  4. Add Integer Overflow Checks: Add a condition to check for integer overflow in the constructor's loop to prevent unexpected behavior.

  5. Code Auditing: Conduct a comprehensive security audit of the entire contract to identify and address any additional vulnerabilities that might be present.

  6. Use Latest Solidity Version: Consider using the latest version of Solidity to leverage security enhancements and bug fixes.

Addressing these recommendations will significantly improve the security of the ProxyFactory contract and minimize the risk of potential exploits.

PatrickAlphaC commented 1 year ago

vague generalities are insufficient for a valid finding. please provide a PoC to be reconsidered.