CVE-2023-27495 – @fastify/csrf-protection

Package

Manager: npm
Name: @fastify/csrf-protection
Vulnerable Version: >=0 <4.1.0 || >=5.0.0 <6.3.0

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

EPSS: 0.00112 pctl0.30389

Details

Bypass of CSRF protection in the presence of predictable userInfo ## Description The [CSRF](https://owasp.org/www-community/attacks/csrf) protection enforced by the `@fastify/csrf-protection` library in combination with `@fastify/cookie` can be bypassed from network and same-site attackers under certain conditions. `@fastify/csrf-protection` supports an optional `userInfo` parameter that binds the CSRF token to the user. This parameter has been introduced to prevent cookie-tossing attacks as a fix for [CVE-2021-29624](https://www.cvedetails.com/cve/CVE-2021-29624). Whenever `userInfo` parameter is missing, or its value can be predicted for the target user account, network and [same-site](https://canitakeyoursubdomain.name/) attackers can 1. fixate a `_csrf` cookie in the victim's browser, and 2. forge CSRF tokens that are valid for the victim's session. This allows attackers to bypass the CSRF protection mechanism. As a fix, `@fastify/csrf-protection` starting from version 6.3.0 (and v4.1.0) includes a server-defined secret `hmacKey` that cryptographically binds the CSRF token to the value of the `_csrf` cookie and the `userInfo` parameter, making tokens non-spoofable by attackers. This protection is effective as long as the `userInfo` parameter is unique for each user. ### Patches This is patched in version 6.3.0 and v4.1.0. ### Workarounds As a workaround, developers can use a random, non-predictable `userInfo` parameter for each user. ## Credits * Pedro Adão (@pedromigueladao), [Instituto Superior Técnico, University of Lisbon](https://tecnico.ulisboa.pt/) * Marco Squarcina (@lavish), [Security & Privacy Research Unit, TU Wien](https://secpriv.wien/)

Metadata

Created: 2023-04-20T21:18:51Z
Modified: 2023-05-02T12:31:41Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/04/GHSA-qrgf-9gpc-vrxw/GHSA-qrgf-9gpc-vrxw.json
CWE IDs: ["CWE-352"]
Alternative ID: GHSA-qrgf-9gpc-vrxw
Finding: F007
Auto approve: 1