Auth bypass in Goauthentik Authentik

CVE-2024-23647

Authentik is an open-source Identity Provider. There is a bug in our implementation of PKCE that allows an attacker to circumvent the protection that PKCE offers. PKCE adds the code_challenge parameter to the authorization request and adds the code_verifier parameter to the token request. Prior to 2023.8.7 and 2023.10.7, a downgrade scenario is possible: if the attacker removes the code_challenge parameter from the authorization request, authentik will not do the PKCE check. Because of this bug, an attacker can circumvent the protection PKCE offers, such as CSRF attacks and code injection attacks. Versions 2023.8.7 and 2023.10.7 fix the issue.

Vulnerability class: Broken Authentication

EPSS: 0.005 (42.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-23647?
CVE-2024-23647 is a medium-severity vulnerability in Goauthentik Authentik, classified under Improper Authentication. CVSS score: 6.5/10. Published 2024-01-30.
How severe is CVE-2024-23647?
Medium severity. CVSS v3 base score is 6.5 out of 10.