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Vulnerability · Published Aug 7, 2023 · Assigned by GitHub_M

CVE-2023-39363Vyper incorrectly allocated named re-entrancy locks

Critical 9.1

In plain English

A critical-severity incorrect authorization in vyper from vyperlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 57% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)9.1Critical
Exploit odds (30 days)0.8%top 42.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Vyper 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
PyPIvyper0.3.1GHSA-5824-cm3x-3c38
PyPIvyperno fix listedPYSEC-2023-142

Affected products (as reported)

VendorProductVersions
vyperlang vyper = 0.2.15= 0.2.16= 0.3.0

Weakness: CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:A

References