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Fastify: Incorrect Content-Type parsing can lead to CSRF attack

Moderate severity GitHub Reviewed Published Nov 21, 2022 in fastify/fastify • Updated Jan 31, 2023

Package

npm fastify (npm)

Affected versions

>= 4.0.0, < 4.10.2
>= 3.0.0, < 3.29.4

Patched versions

4.10.2
3.29.4

Description

Impact

The attacker can use the incorrect Content-Type to bypass the Pre-Flight checking of fetch. fetch() requests with Content-Type’s essence as "application/x-www-form-urlencoded", "multipart/form-data", or "text/plain", could potentially be used to invoke routes that only accepts application/json content type, thus bypassing any CORS protection, and therefore they could lead to a Cross-Site Request Forgery attack.

Patches

For 4.x users, please update to at least 4.10.2
For 3.x users, please update to at least 3.29.4

Workarounds

Implement Cross-Site Request Forgery protection using @fastify/csrf.

References

Check out the HackerOne report: https://hackerone.com/reports/1763832.

For more information

Fastify security policy

References

@mcollina mcollina published to fastify/fastify Nov 21, 2022
Published to the GitHub Advisory Database Nov 21, 2022
Reviewed Nov 21, 2022
Published by the National Vulnerability Database Nov 22, 2022
Last updated Jan 31, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(42nd percentile)

Weaknesses

Cross-Site Request Forgery (CSRF)

The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. Learn more on MITRE.

CVE ID

CVE-2022-41919

GHSA ID

GHSA-3fjj-p79j-c9hh

Source code

Credits

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