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@fastify/secure-session: Reuse of destroyed secure session cookie

High severity GitHub Reviewed Published Apr 10, 2024 in fastify/fastify-secure-session • Updated May 15, 2024

Package

npm @fastify/secure-session (npm)

Affected versions

< 7.3.0

Patched versions

7.3.0

Description

Impact

At the end of the request handling, it will encrypt all data in the session with a secret key and attach the ciphertext as a cookie value with the defined cookie name. After that, the session on the server side is destroyed. When an encrypted cookie with matching session name is provided with subsequent requests, it will decrypt the ciphertext to get the data. The plugin then creates a new session with the data in the ciphertext. Thus theoretically the web instance is still accessing the data from a server-side session, but technically that session is generated solely from a user provided cookie (which is assumed to be non-craftable because it is encrypted with a secret key not known to the user).

The issue exists in the session removal process. In the delete function of the code, when the session is deleted, it is marked for deletion. However, if an attacker could gain access to the cookie, they could keep using it forever.

Patches

Fixed in 56d66642ecc633cff0606927601e81cdac361370.
Update to v7.3.0.

Workarounds

Include a "last update" field in the session, and treat "old sessions" as expired.
Make sure to configure your cookie as "http only".

References

References

@mcollina mcollina published to fastify/fastify-secure-session Apr 10, 2024
Published to the GitHub Advisory Database Apr 10, 2024
Reviewed Apr 10, 2024
Published by the National Vulnerability Database Apr 10, 2024
Last updated May 15, 2024

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
Required
Scope
Changed
Confidentiality
High
Integrity
None
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:C/C:H/I:N/A:N

EPSS score

0.043%
(10th percentile)

Weaknesses

CVE ID

CVE-2024-31999

GHSA ID

GHSA-9wwp-q7wq-jx35

Credits

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