Authlib is a Python library which builds OAuth and OpenID Connect servers. In versions 1.0.0 through 1.6.5, cache-backed state/request-token storage is not tied to the initiating user session, so CSRF is possible for any attacker that has a valid state (easily obtainable via an attacker-initiated authentication flow). When a cache is supplied to the OAuth client registry, FrameworkIntegration.set_state_data writes the entire state blob under state{app}_{state}, and get_state_data ignores the caller’s session altogether. This issue has been patched in version 1.6.6.
Exploitability
AV:NAC:LPR:LUI:RScope
S:UImpact
C:HI:NA:N5.7/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:NAuthentication