This security advisory relates to a capability for an attacker to exploit a reflected cross-site scripting vulnerability when using the @keystone-6/auth package.

Impact

The vulnerability can impact users of the administration user interface when following an untrusted link to the signin or init page.
This is a targeted attack and may present itself in the form of phishing and or chained in conjunction with some other vulnerability.

Vulnerability mitigation

Please upgrade to @keystone-6/auth >= 1.0.2, where this vulnerability has been closed.
If you are using @keystone-next/auth, we strongly recommend you upgrade to @keystone-6.

Workarounds

If for some reason you cannot upgrade the dependencies in software, you could alternatively

• disable the administration user interface, or
• if using a reverse-proxy, strip query parameters when accessing the administration interface

References

https://owasp.org/www-community/attacks/xss/

Thanks to Shivansh Khari (@Shivansh-Khari) for discovering and reporting this vulnerability