OAuth2: PKCE can be fully circumvented
Summary
OAuth2: PKCE can be fully circumvented
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- patch github.com
- web github.com
- web github.com
- web github.com