Description
An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used in its place and checked against the configured required scopes. These are different concepts, and the audience claim does not describe what a token is allowed to do. A token that grants no relevant permissions can be accepted because its intended recipient value happens to match a configured scope name, granting access that should have been denied. It also hides an identity provider misconfiguration where scopes are not being issued at all. Ensure the identity provider issues a scope claim for all tokens used with Dovecot, and that configured scope names do not match audience values. Update to non-vulnerable version. No publicly available exploits are known.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Open-Xchange GmbH OX Dovecot Pro
Default version status: unaffected
2.3.13 to < 2.3.22.2affected3.0.0 to < 3.0.7affected3.1.0 to < 3.1.6affected
Open-Xchange GmbH OX Dovecot CE
Default version status: unaffected
2.3.13 to < 2.4.5affected