CVE-2016-5009

What it actually does

The handle_command function in mon/Monitor.cc crashes the Ceph monitor with a segmentation fault when an authenticated user supplies an empty or specially crafted command prefix.

Why it matters to the business

Disruption of Ceph cluster monitoring can halt storage management operations and force restarts, affecting availability of dependent services until the monitor recovers.

How an attack unfolds

An authenticated remote attacker connects to the Ceph monitor service and issues a command with an empty or malformed prefix, triggering the vulnerable code path that causes an immediate segmentation fault and process crash.

How to fix it

Upgrade Ceph to a build containing commit 957ece7e95d8f8746191fd9629622d4457d690d6; for Chainguard and Wolfi istio-operator-1.19 packages, update to the fixed 0 revision that pulls the corrected Ceph dependency.

How to confirm the fix worked

Verify the running Ceph binary or package contains commit 957ece7e95d8f8746191fd9629622d4457d690d6; attempt to reproduce the crash with an empty prefix command in a test environment and confirm the monitor remains stable.

Typical attack path

1. Obtain valid credentials for a Ceph monitor user
2. Connect to the monitor service over the network
3. Send a command containing an empty or crafted prefix
4. Trigger segmentation fault resulting in monitor crash

How to detect it

Inspect Ceph monitor logs for repeated segmentation fault entries or abrupt process terminations around the time of command handling; correlate with authentication events showing unusual prefix values.

• segmentation fault
• ceph-mon.*crash
• handle_command

What your security team should do

• Apply the fixed Ceph commit or package revision immediately on all monitor nodes
• Restrict network access to monitor ports to only trusted clients
• Enable and review Ceph monitor crash and audit logs for segmentation faults