Missing authorization in illumos zonestatd allows local users to disrupt zonestat and enumerate running zones

Summary

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 caller's 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.

Timeline

1. Oct 9, 2026, 2:18 PM UTCCVE published
2. Oct 9, 2026, 4:15 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Oct 9, 2026, 4:45 PM UTCRecord last updated

Affected versions

• system/zones

  From efd4c9b63ad77503c101fc6c2ed8ba96c9d52964 · fixed in 865b58d24a0f1a31c838bffc3a7193d3345fe5ba

• OmniOS OmniOS

  From any · fixed in r151054; From r151058 · fixed in r151058w; From r151056 · fixed in r151056aw; From r151054 · fixed in r151054bw

References 3