CVE-2023-39363 Information

Description

Vyer is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). In versions 0.2.15 0.2.16 and 0.3.0 named re-entrancy locks are allocated incorrectly. Each function using a named re-entrancy lock gets a unique lock regardless of the key allowing cross-function re-entrancy in contracts compiled with the susceptible versions. A specific set of conditions is required to result in misbehavior of affected contracts specifically: a .vy contract compiled with vyper versions 0.2.15 0.2.16 or 0.3.0; a primary function that utilizes the @nonreentrant decorator with a specific key and does not strictly follow the check-effects-interaction pattern (i.e. contains an external call to an untrusted party before storage updates); and a secondary function that utilizes the same key and would be affected by the improper state caused by the primary function. Version 0.3.1 contains a fix for this issue.

Reference

https://github.com/vyperlang/vyper/security/advisories/GHSA-5824-cm3x-3c38 https://hackmd.io/@LlamaRisk/BJzSKHNjn https://hackmd.io/@vyperlang/HJUgNMhs2 https://github.com/vyperlang/vyper/pull/2514 https://github.com/vyperlang/vyper/pull/2439