QID 980061

Security update has been released for github.com/ory/fosite to fix the vulnerability.

Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

[fosite#400](https://github.com/ory/fosite/pull/400) (released as v0.30.2) introduced a new feature for handling redirect URLs pointing to loopback interfaces ([rfc8252#section-7.3](https://tools.ietf.org/html/rfc8252#section-7.3)). As part of that change new behavior was introduced which failed to respect the redirect URL's (only for loopback interfaces!) query parameters

1. Registering a client with allowed redirect URL `http://127.0.0.1/callback`
2. Performing OAuth2 flow and requesting redirect URL `http://127.0.0.1/callback?bar=foo`
3. Instead of an error, the browser is redirected to `http://127.0.0.1/callback?bar=foo` with a potentially successful OAuth2 response.

as well as the host parameter (as long as the host is a loopback interface):

1. Registering a client with allowed redirect URL `https://example.com/callback`
2. Performing OAuth2 flow and requesting redirect URL `http://127.0.0.1/callback`
3. Instead of an error, the browser is redirected to `http://127.0.0.1/callback` with a potentially successful OAuth2 response.

These bugs are only applicable in scenarios where the attacker has control over the loopback interface (`localhost`, `127.0.0.1`, `[::1]`) where the browser performing the OAuth2 flow is running.