CVE-2023-48228 | OAuth2: PKCE can be fully circumvented
Exp
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.
Conclusion & alert: CVE-2023-48228 is rated High Exploit Risk (72.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.14%).Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB).Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Public exploit references (Exploit-DB) for CVE-2023-48228
Exploit prediction scoring system (EPSS) score for CVE-2023-48228
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).