{"id":"CVE-2023-48228","summary":"OAuth2: PKCE can be fully circumvented","details":"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.","aliases":["GHSA-fm34-v8xq-f2c3"],"modified":"2026-04-10T05:04:39.939288Z","published":"2023-11-21T20:48:32.552Z","database_specific":{"cwe_ids":["CWE-287"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/48xxx/CVE-2023-48228.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/goauthentik/authentik/blob/dd4e9030b4e667d3720be2feda24c08972602274/authentik/providers/oauth2/views/token.py#L225"},{"type":"WEB","url":"https://github.com/goauthentik/authentik/releases/tag/version%2F2023.10.4"},{"type":"WEB","url":"https://github.com/goauthentik/authentik/releases/tag/version%2F2023.8.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/48xxx/CVE-2023-48228.json"},{"type":"ADVISORY","url":"https://github.com/goauthentik/authentik/security/advisories/GHSA-fm34-v8xq-f2c3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-48228"},{"type":"FIX","url":"https://github.com/goauthentik/authentik/commit/3af77ab3821fe9c7df8055ba5eade3d1ecea03a6"},{"type":"FIX","url":"https://github.com/goauthentik/authentik/commit/6b9afed21f7c39f171a4a445654cfe415bba37d5"},{"type":"FIX","url":"https://github.com/goauthentik/authentik/commit/b88e39411c12e3f9e04125a7887f12354f760a14"},{"type":"FIX","url":"https://github.com/goauthentik/authentik/pull/7666"},{"type":"FIX","url":"https://github.com/goauthentik/authentik/pull/7668"},{"type":"FIX","url":"https://github.com/goauthentik/authentik/pull/7669"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/goauthentik/authentik","events":[{"introduced":"ed46fd629efd4307040c494faaec544a5cb7b3ee"},{"fixed":"1516fe86dab2f62754a9c37679e0488dcf829c77"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-48228.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}