Potential race condition due to use of approve function [code-improvement]

[0xM3R]

File: transfer.ts
Issue: Use of the approve function, leading to potential race condition vulnerabilities.

Analysis

The vulnerable implementation is as follows:

const approveTx = await nftContract
    .connect(signer)
    .approve(args.from, args.tokenId);

• Approve Function: Using approve can introduce race conditions if not managed properly.

How It Can Be Harmful

• Race Conditions: Attackers can exploit timing issues to execute unauthorized transactions.

How to Mitigate the Issue

1. Avoid approve When Possible: Use safeTransferFrom for direct transfers.

await nftContract
    .connect(signer)
    .safeTransferFrom(signer.address, args.to, args.tokenId);

2. Implement Safe Approvals: If approve is necessary, ensure it's used safely by setting allowances to zero before updating them.

References

• ERC20 Approve Race Condition Vulnerability
  Explains the risks associated with the approve function in ERC20 tokens.
  Zokyo Auditing Tutorials
• CVE-2024-6409
  Discusses a race condition vulnerability in OpenSSH's server signal handling.
  CVE Details