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fastify vulnerable to denial of service via malicious Content-Type

High severity GitHub Reviewed Published Oct 10, 2022 in fastify/fastify • Updated Feb 2, 2023

Package

npm fastify (npm)

Affected versions

>= 4.0.0, < 4.8.1

Patched versions

4.8.1

Description

Impact

An attacker can send an invalid Content-Type header that can cause the application to crash, leading to a possible Denial of Service attack. Only the v4.x line is affected.

(This was updated: upon a close inspection, v3.x is not affected after all).

Patches

Yes, update to > v4.8.0.

Workarounds

You can reject the malicious content types before the body parser enters in action.

  const badNames = Object.getOwnPropertyNames({}.__proto__)
  fastify.addHook('onRequest', async (req, reply) => {
    for (const badName of badNames) {
      if (req.headers['content-type'].indexOf(badName) > -1) {
        reply.code(415)
        throw new Error('Content type not supported')
      }
    }
  })

References

See the HackerOne report #1715536

For more information

Fastify security policy

References

@mcollina mcollina published to fastify/fastify Oct 10, 2022
Published by the National Vulnerability Database Oct 10, 2022
Published to the GitHub Advisory Database Oct 11, 2022
Reviewed Oct 11, 2022
Last updated Feb 2, 2023

Severity

High

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
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.166%
(54th percentile)

Weaknesses

CVE ID

CVE-2022-39288

GHSA ID

GHSA-455w-c45v-86rg

Source code

Credits

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