Dapr Sentry's OIDC discovery endpoint derives the issuer and jwks_uri of the /.well-known/openid-configuration document from the request Host, honoring an attacker-controlled X-Forwarded-Host header without validation when no allowed-hosts list is configured (the default), and serves the document with a one-hour public cache lifetime. A remote unauthenticated attacker can poison the discovery document so relying parties performing dynamic (unpinned) discovery fetch the JWKS from an attacker-controlled server, causing attacker-signed JWTs to be accepted. Exploitation requires the OIDC server enabled without a configured jwt-issuer or oidc-allowed-hosts.
Exploitability
AV:NAC:LAT:PPR:NUI:NVulnerable System
VC:NVI:HVA:NSubsequent System
SC:NSI:NSA:N8.2/CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NOther