Vyper
CVE-2023-39363
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization logic validation
MITRE ATT&CK
1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.1 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could bypass authorization checks to access restricted resources by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Review and test authorization logic, implement consistent access control checks, use centralized authorization framework.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in pypi
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Incorrect Authorization (CWE-863), which allows attackers to bypass authorization checks to access restricted resources. 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 products include: Vyperlang Vyper. Version information: Version 0.3.1.
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Severity by source
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
Primary rating from Vendor (github) · only source for this CVE.
CVSS VectorVendor: github
DescriptionCVE.org
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.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Affected Products (CPE)CVE.org
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine. Rated critical severity (CVSS 9.8), this v
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. Rated critical severity (CVSS 9.8), this v
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine. Rated critical severity (CVSS 9.8), this v
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. Rated critical severity (CVSS 9.8), this v
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Rated critical severity (CVSS 9.1), this v
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Rated high severity (CVSS 8.1), this
Vyper is a Pythonic Smart Contract Language for the EVM. Rated high severity (CVSS 7.5), this vulnerability is remotely
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Rated high severity (CVSS 7.5), this vulne
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Rated high severity (CVSS 7.5), this vulne
Vyper is a pythonic smart contract language for the EVM. Rated high severity (CVSS 7.5), this vulnerability is remotely
Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. Rated high severity (CVSS 7.5), this vulne
Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. Rated high severity (CVSS 7.5), this vulne
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