CVE-2023-31146 HIGH

CVE-2023-31146: Vyper vulnerable to OOB DynArray access when array is on both LHS and RHS of an assignment

Vendor Vyperlang
Product vyper
Weakness CWE-787
Published May 11, 2023
Last update January 24, 2025

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

What the vulnerability does

01Description

Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, during codegen, the length word of a dynarray is written before the data, which can result in out-of-bounds array access in the case where the dynarray is on both the lhs and rhs of an assignment. The issue can cause data corruption across call frames. The expected behavior is to revert due to out-of-bounds array access. Version 0.3.8 contains a patch for this issue.

Key dates

02Disclosure timeline

May 11, 2023 CVE published
January 24, 2025 Record updated