Paper/Archive/CVE-2023-48228

CVE-2023-48228

goauthentik authentik — OAuth2: PKCE can be fully circumvented

CVSS 9.8 (NVD)9.8 / 10 × 3029.4 Not in CISA KEV+300.0 EPSS percentile 69.3.693 × 2013.9 No public exploit+100.0 SSVC exploitation: unknown+100.0

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource

authentik< 2023.10.4–CNA

authentik< 2023.8.5–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

GitHub_M (CNA)7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References