What is CVE-2023-29019?

CVE-2023-29019 is a high-severity security vulnerability in @fastify/passport (npm), affecting versions < 1.1.0. It is fixed in 1.1.0, 2.3.0.

How severe is CVE-2023-29019?

CVE-2023-29019 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of @fastify/passport are affected by CVE-2023-29019?

@fastify/passport (npm) versions < 1.1.0 is affected.

Is there a fix for CVE-2023-29019?

Yes. CVE-2023-29019 is fixed in 1.1.0, 2.3.0. Upgrade to this version or later.

Is CVE-2023-29019 exploitable, and should I be worried?

Whether CVE-2023-29019 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2023-29019 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2023-29019?

Upgrade: @fastify/passport to 1.1.0 or later, @fastify/passport to 2.3.0 or later.

CVE-2023-29019 in @fastify/passport

Q: How severe is CVE-2023-29019?

CVE-2023-29019 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of @fastify/passport are affected by CVE-2023-29019?

@fastify/passport (npm) versions < 1.1.0 is affected.

Q: Is there a fix for CVE-2023-29019?

Yes. CVE-2023-29019 is fixed in 1.1.0, 2.3.0. Upgrade to this version or later.

Q: Is CVE-2023-29019 exploitable, and should I be worried?

Whether CVE-2023-29019 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2023-29019 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2023-29019?

Upgrade: @fastify/passport to 1.1.0 or later, @fastify/passport to 2.3.0 or later.

Summary

Session fixation in fastify-passport

Applications using @fastify/passport for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers.

Details

fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website.

Credits

Pedro Adão (@pedromigueladao), Instituto Superior Técnico, University of Lisbon
Marco Squarcina (@lavish), Security & Privacy Research Unit, TU Wien

Impact

CVE-2023-29019 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.1.0, 2.3.0); upgrading removes the vulnerable code path.

Affected versions

@fastify/passport (< 1.1.0) @fastify/passport (>= 2.0.0, < 2.3.0)

Security releases

@fastify/passport → 1.1.0 (npm) @fastify/passport → 2.3.0 (npm)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session.

Frequently Asked Questions

What is CVE-2023-29019? CVE-2023-29019 is a high-severity security vulnerability in @fastify/passport (npm), affecting versions < 1.1.0. It is fixed in 1.1.0, 2.3.0.
How severe is CVE-2023-29019? CVE-2023-29019 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of @fastify/passport are affected by CVE-2023-29019? @fastify/passport (npm) versions < 1.1.0 is affected.
Is there a fix for CVE-2023-29019? Yes. CVE-2023-29019 is fixed in 1.1.0, 2.3.0. Upgrade to this version or later.
Is CVE-2023-29019 exploitable, and should I be worried? Whether CVE-2023-29019 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2023-29019 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2023-29019?
- Upgrade @fastify/passport to 1.1.0 or later
- Upgrade @fastify/passport to 2.3.0 or later

Other vulnerabilities in @fastify/passport

CVE-IDSeverityPackage summary

CVE-2023-29020Medium@fastify/passport: CSRF token fixation in fastify-passport