CVE-2023-48228

Public Exploit
OAuth2: PKCE can be fully circumvented

Description

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.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.70% Top 30%
Vendor Advisory github.com
Affected: goauthentik authentik
Published at:
Updated at:

References

Link Tags
https://github.com/goauthentik/authentik/security/advisories/GHSA-fm34-v8xq-f2c3 vendor advisory exploit
https://github.com/goauthentik/authentik/pull/7666 patch
https://github.com/goauthentik/authentik/pull/7668 patch
https://github.com/goauthentik/authentik/pull/7669 patch
https://github.com/goauthentik/authentik/commit/3af77ab3821fe9c7df8055ba5eade3d1ecea03a6 patch
https://github.com/goauthentik/authentik/commit/6b9afed21f7c39f171a4a445654cfe415bba37d5 patch
https://github.com/goauthentik/authentik/commit/b88e39411c12e3f9e04125a7887f12354f760a14 patch
https://github.com/goauthentik/authentik/blob/dd4e9030b4e667d3720be2feda24c08972602274/authentik/providers/oauth2/views/token.py#L225 product
https://github.com/goauthentik/authentik/releases/tag/version%2F2023.10.4 release notes
https://github.com/goauthentik/authentik/releases/tag/version%2F2023.8.5 release notes

Frequently Asked Questions

What is the severity of CVE-2023-48228?
CVE-2023-48228 has been scored as a high severity vulnerability.
How to fix CVE-2023-48228?
To fix CVE-2023-48228, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-48228 being actively exploited in the wild?
It is possible that CVE-2023-48228 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-48228?
CVE-2023-48228 affects goauthentik authentik.
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