Files
netbird/management/internals
Maycon Santos f65f7b347e [management] Deny reverse proxy access to pending and blocked users (#7105)
A user in the Pending Approval state could complete SSO and reach any
SSO-protected reverse proxy service distributed to a group they belong
to, including the All Users group. The reverse proxy authorization path
checked the session token signature, that the user exists, that the
user's account matches the service's account, and group membership —
never the user's account status. The REST API (`permissions/manager.go`)
and peer registration both gate on that state, but the proxy gRPC
service does not go through the permissions manager, so neither gate
applied. A pending user is persisted as blocked and pending approval, so
blocked users reached those services the same way.

`ValidateSession` now denies on account status, reporting
`pending_approval` or `user_blocked` so the proxy access log and the
denied page carry the cause rather than a generic refusal.
`GenerateSessionToken` refuses to mint a token for such a user at all,
so the browser never receives a session cookie and the OIDC callback can
tell the user why instead of showing "Service configuration error".
`ValidateUserGroupAccess` and `ValidateTunnelPeer` close the same gap;
for the tunnel path this covers a user blocked after their peer was
registered, since peer group membership alone kept mesh-origin access
open.

A single helper produces both the denied reason for the RPC responses
and the sentinel error for the error-returning callers, so the four
entry points cannot drift apart. A user the store cannot resolve is
denied rather than passed through.

One thing deliberately left out: session cookies are validated locally
by the proxy against the service public key with no management
round-trip, so a cookie issued before a user is blocked stays valid
until it expires (24h by default). That is a revocation-propagation
problem rather than this authorization gap, and every option for it
(per-request validation with a cache, short-lived tokens with refresh,
push-based revocation) changes the proxy hot path or the
proxy/management protocol. Worth its own ticket.
2026-08-08 20:48:34 +09:00
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