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Prototype poisoning in fastify-multipart

High
mcollina published GHSA-qh73-qc3p-rjv2 Feb 11, 2022

Package

npm fastify-multipart (npm)

Affected versions

<= v5.3.0

Patched versions

>= v5.3.1

Description

Impact

This is a bypass of CVE-2020-8136 (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8136).
By providing a name=constructor property it is still possible to crash the application.
The original fix only checks for the key __proto__ (#116).

All users are recommended to upgrade

Patches

v5.3.1 includes a patch

Workarounds

No workarounds are possible.

References

Read up https://www.fastify.io/docs/latest/Guides/Prototype-Poisoning/

For more information

If you have any questions or comments about this advisory:

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

CVE ID

CVE-2021-23597

Weaknesses

Uncaught Exception

An exception is thrown from a function, but it is not caught. Learn more on MITRE.

Credits