CVE-2024-24564: Vyper extract32 can ready dirty memory

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-02-26 · updated 2026-06-17
Weakness: CWE-125

Description

Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. When using the built-in `extract32(b, start)`, if the `start` index provided has for side effect to update `b`, the byte array to extract `32` bytes from, it could be that some dirty memory is read and returned by `extract32`. This vulnerability is fixed in 0.4.0.

Affected products

vyperlang vyper: before 0.4.0 — fixed in 0.4.0

How to fix

Upgrade to a fixed version: vyperlang vyper 0.4.0. Check the vendor advisory for mitigations.

References

https://github.com/vyperlang/vyper/commit/3d9c537142fb99b2672f21e2057f5f202cde194f
https://github.com/vyperlang/vyper/security/advisories/GHSA-4hwq-4cpm-8vmx
https://github.com/vyperlang/vyper/security/advisories/GHSA-4hwq-4cpm-8vmx

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