CVSS8.1
Severityhigh
WeaknessCWE-601
ExploitedNot in CISA KEV
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Description
Stalwart Mail Server does not compare an OAuth redirect target against any registered destination in its default configuration. The validation routine in crates/http/src/auth/oauth/registration.rs returns success immediately when the client-authentication requirement is disabled, and that requirement is false in the shipped settings, so the supplied redirect value is neither matched against a registered client nor otherwise constrained. The value is stored with the authorization code, and the login page reads it back and sends the browser to it with the code attached. A request naming a destination the attacker controls therefore delivers a valid authorization code there once the account hol