Fastify
CVE-2023-31999
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V3 - Web Frontend Security Anti-CSRF tokens, SameSite cookies
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 8.8 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could trick authenticated users into performing unintended actions by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
All versions of @fastify/oauth2 used a statically generated state parameter at startup time and were used across all requests for all users. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement anti-CSRF tokens, validate Origin/Referer headers, use SameSite cookie attribute.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
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 Cross-Site Request Forgery (CSRF) (CWE-352), which allows attackers to trick authenticated users into performing unintended actions. All versions of @fastify/oauth2 used a statically generated state parameter at startup time and were used across all requests for all users. The purpose of the Oauth2 state parameter is to prevent Cross-Site-Request-Forgery attacks. As such, it should be unique per user and should be connected to the user's session in some way that will allow the server to validate it. v7.2.0 changes the default behavior to store the state in a cookie with the http-only and same-site=lax attributes set. The state is now by default generated for every user. Note that this contains a breaking change in the checkStateFunction function, which now accepts the full Request object. Affected products include: Fastify Oauth2.
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
All versions of @fastify/oauth2 used a statically generated state parameter at startup time and were used across all requests for all users. The purpose of the Oauth2 state parameter is to prevent Cross-Site-Request-Forgery attacks. As such, it should be unique per user and should be connected to the user's session in some way that will allow the server to validate it.
v7.2.0 changes the default behavior to store the state in a cookie with the http-only and same-site=lax attributes set. The state is now by default generated for every user. Note that this contains a breaking change in the checkStateFunction function, which now accepts the full Request object.
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
Cross-Site Request Forgery exploits the automatic credential inclusion behavior of web browsers.
Affected Products (CPE)NVD
A redirect vulnerability in the `fastify-static` module version >= 4.2.4 and < 4.4.1 allows remote attackers to redirect
Fastify is a fast and low overhead web framework, for Node.js. Rated high severity (CVSS 7.5), this vulnerability is rem
Prototype pollution vulnerability in fastify-multipart < 1.0.5 allows an attacker to crash fastify applications parsing
Fastify node module before 0.38.0 is vulnerable to a denial-of-service attack by sending a request with "Content-Type: a
A denial of service vulnerability exists in Fastify v2.14.1 and v3.0.0-rc.4 that allows a malicious user to trigger reso
A redirect vulnerability in the fastify-static module version < 4.2.4 allows remote attackers to redirect users to arbit
Authorization bypass in the @fastify/express middleware-compatibility plugin (versions 4.0.6 and earlier) lets unauthent
Authentication bypass in @fastify/express v4.0.4 and earlier allows remote unauthenticated attackers to access protected
Middleware bypass in Fastify Express plugin (fastify/express) allows complete circumvention of authentication, authoriza
Fastify is a web framework with minimal overhead and plugin architecture. Rated high severity (CVSS 8.8), this vulnerabi
Authentication and authorization bypass in @fastify/middie (Node.js middleware library for Fastify) allows remote unauth
Schema authorization bypass in Fastify before 5.12.2 allows an authenticated low-privilege attacker to substitute an arb
Exploit-DB