Auth bypass in Goauthentik Authentik

CVE-2023-48228

authentik is an open-source identity provider. When initialising a oauth2 flow with a `code_challenge` and `code_method` (thus requesting PKCE), the single sign-on provider (authentik) must check if there is a matching and existing `code_verifier` during the token step. Prior to versions 2023.10.4 and 2023.8.5, authentik checks if the contents of `code_verifier` is matching only when it is provided. When it is left out completely, authentik simply accepts the token request with out it; even when the flow was started with a `code_challenge`. authentik 2023.8.5 and 2023.10.4 fix this issue.

Vulnerability class: Broken Authentication

EPSS: 0.012 (66.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-48228?
CVE-2023-48228 is a high-severity vulnerability in Goauthentik Authentik, classified under Improper Authentication. CVSS score: 7.5/10. Published 2023-11-21.
How severe is CVE-2023-48228?
High severity. CVSS v3 base score is 7.5 out of 10.