CVE-2021-41121 Explained : Impact and Mitigation

Vyper is a Pythonic Smart Contract Language for the EVM. An issue in versions prior to 0.3.0 leads to memory corruption due to an incorrect pointer, posing a high severity risk.

Understanding CVE-2021-41121

In affected versions of Vyper, a memory corruption vulnerability was identified, impacting the way function calls are processed within literal structs.

What is CVE-2021-41121?

The vulnerability arises from an incorrect pointer to the stack's top during function calls within literal structs, resulting in memory corruption.

The Impact of CVE-2021-41121

The vulnerability has a CVSS base score of 7.5 (High) and affects confidentiality, integrity, and availability due to memory corruption issues.

Technical Details of CVE-2021-41121

This section covers specific technical aspects of the vulnerability in Vyper.

Vulnerability Description

The vulnerability in Vyper versions < 0.3.0 triggers memory corruption when executing function calls in literal structs due to an incorrect pointer to the stack's top.

Affected Systems and Versions

Product: Vyper
Vendor: Vyperlang
Versions Affected: < 0.3.0

Exploitation Mechanism

The vulnerability can be exploited by performing a function call inside a literal struct, causing memory corruption from an incorrect stack pointer.

Mitigation and Prevention

To address CVE-2021-41121, follow these mitigation steps and best security practices.

Immediate Steps to Take

Upgrade Vyper to version 0.3.0 or later to mitigate the memory corruption vulnerability.
Monitor official sources for security advisories and patches.

Long-Term Security Practices

Conduct regular security audits and code reviews to identify and address vulnerabilities.
Train developers to write secure code and adhere to best practices.

Patching and Updates

Apply all security patches and updates promptly to ensure protection against known vulnerabilities.