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NovaApplication · Openstack

CVE-2017-16239

MEDIUM · 6.5 CVSS v3.0 Published 2017-11-14
Fix available
A fix is available. Upgrade to after 14.0.9 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In OpenStack Nova through 14.0.9, 15.x through 15.0.7, and 16.x through 16.0.2, by rebuilding an instance, an authenticated user may be able to circumvent the Filter Scheduler bypassing imposed filters (for example, the ImagePropertiesFilter or the IsolatedHostsFilter). All setups using Nova Filter Scheduler are affected. Because of the regression described in Launchpad Bug #1732947, the preferred fix is a 14.x version after 14.0.10, a 15.x version after 15.0.8, or a 16.x version after 16.0.3.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In OpenStack Nova versions through 14.0.9, 15.0.7, and 16.0.2, the Filter Scheduler is bypassed during instance rebuild operations, allowing authenticated users to potentially deploy instances on hosts that should be filtered out by filters such as ImagePropertiesFilter or IsolatedHostsFilter. This is a regression from Launchpad Bug #1732947 where the scheduler filters are not applied when rebuilding an instance.

MitigationUpgrade Nova to version 14.0.10+, 15.0.8+, or 16.0.3+ to ensure Filter Scheduler filters are properly applied during instance rebuild operations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
NovaApplication
Affected:<= 14.0.9= 15.0.0= 15.0.1= 15.0.2= 15.0.3= 15.0.4= 15.0.5= 15.0.6= 15.0.7= 16.0.0= 16.0.1= 16.0.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Nova version
    Run `nova-manage --version` or check the Nova package version installed on the controller node
    Affected if The version is 14.0.9 or earlier, 15.0.0-15.0.7, or 16.0.0-16.0.2
  2. Verify Filter Scheduler is in use
    Check the `scheduler_driver` option in the Nova configuration file (typically nova.conf) under the [DEFAULT] section
    Affected if The scheduler_driver is set to `filter_scheduler.FilterScheduler` or another filter-based scheduler
  3. Confirm ImagePropertiesFilter is enabled
    Check the `enabled_filters` or `available_filters` option in the Nova scheduler configuration
    Affected if `ImagePropertiesFilter` appears in the list of enabled filters for the scheduler
  4. Confirm IsolatedHostsFilter is enabled
    Check the Nova scheduler configuration for `IsolatedHostsFilter` in the enabled filters list
    Affected if `IsolatedHostsFilter` appears in the list of enabled filters for the scheduler
  5. Check rebuild operations bypass filters
    Review scheduler logs or perform a test rebuild of an instance to a host that should be filtered out by ImagePropertiesFilter or IsolatedHostsFilter
    Affected if The instance rebuild succeeds on a host that should have been filtered out by the enabled scheduler filters

You are affected if your Nova version falls within 14.0.0-14.0.9, 15.0.0-15.0.7, or 16.0.0-16.0.2 AND you use Filter Scheduler with ImagePropertiesFilter or IsolatedHostsFilter enabled, and rebuild operations bypass these filters.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 14.0.9
Interim mitigation

Upgrade Nova to version 14.0.10+, 15.0.8+, or 16.0.3+ to ensure Filter Scheduler filters are properly applied during instance rebuild operations.

Fix this in Nova Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-16239 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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