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Lack of protection against cookie tossing attacks in fastify-csrf

Moderate
mcollina published GHSA-rc4q-9m69-gqp8 May 14, 2021

Package

npm fastify-csrf (npm)

Affected versions

< 3.1.0

Patched versions

>= 3.1.0

Description

Impact

Users that used fastify-csrf with the "double submit" mechanism using cookies with an application deployed across multiple subdomains, e.g. "heroku"-style platform as a service.

Patches

Version 3.1.0 of the fastify-csrf fixes it.
See #51 and fastify/csrf#2.

The user of the module would need to supply a userInfo when generating the CSRF token to fully implement the protection on their end. This is needed only for applications hosted on different subdomains.

Workarounds

None available.

References

  1. https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html
  2. https://owasp.org/www-pdf-archive/David_Johansson-Double_Defeat_of_Double-Submit_Cookie.pdf

Credits

This vulnerability was found by Xhelal Likaj xhelallikaj20@gmail.com.

For more information

If you have any questions or comments about this advisory:

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
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
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:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVE ID

CVE-2021-29624

Weaknesses