CVE-2023-37902 : Vulnerability Insights and Analysis

This article discusses CVE-2023-37902, a vulnerability affecting Vyper's ecrecover function when a signature does not verify.

Understanding CVE-2023-37902

This CVE highlights a flaw in Vyper's ecrecover function that can lead to undefined data being returned when the signature does not verify.

What is CVE-2023-37902?

Vyper is a Pythonic programming language targeting the Ethereum Virtual Machine (EVM). Prior to version 0.3.10, the ecrecover function fails to fill the output buffer if the signature does not verify, potentially allowing a signature check to pass on an invalid signature.

The Impact of CVE-2023-37902

The impact of this vulnerability includes a potential security bypass where an invalid signature might be accepted if crafted data is placed at memory location 0 before the ecrecover function call.

Technical Details of CVE-2023-37902

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability arises from the ecrecover function in Vyper not properly handling the scenario where the signature fails to verify, leading to undefined data being returned.

Affected Systems and Versions

The affected system is the Vyper programming language, specifically versions earlier than 0.3.10.

Exploitation Mechanism

Exploiting this vulnerability involves manipulating memory to place crafted data at the 0 memory location just before the ecrecover function call.

Mitigation and Prevention

To address CVE-2023-37902, consider the following mitigation strategies.

Immediate Steps to Take

Upgrade to Vyper version 0.3.10 or newer to apply the patch addressing this vulnerability.

Long-Term Security Practices

Follow secure coding practices to minimize the risk of memory manipulation vulnerabilities.

Patching and Updates

Regularly update software components and libraries to ensure you have the latest security patches in place.