A missing authorization check in the illumos zones statistics daemon (zonestatd) allows a local user in any zone to disrupt zonestat in other zones and to determine which zones are running. The zonestatd door server procedure, zsd_server() in usr/src/cmd/zonestat/zonestatd/zonestatd.c, handles the ZSD_CMD_NEW_ZONE command, which is intended to be sent by zoneadmd, without checking the callers credentials. Because the zonestatd door is accessible to all users in every zone, an unprivileged user can send this command with an arbitrary zone ID, causing zonestatd to re-create its door file in that zone, so that new zonestat requests in that zone can fail while the file is replaced. The time taken to handle the command also reveals whether a given zone ID belongs to a running zone. The flaw has existed since 2010 (illumos-gate commit efd4c9b6), and affects any illumos distribution prior to illumos-gate commit 865b58d2.
Weakness
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.