NovaApplication · Openstack

CVE-2017-17051

HIGH · 8.6 CVSS v3.0 Published 2017-12-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges 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
An issue was discovered in the default FilterScheduler in OpenStack Nova 16.0.3. By repeatedly rebuilding an instance with new images, an authenticated user may consume untracked resources on a hypervisor host leading to a denial of service, aka doubled resource allocations. This regression was introduced with the fix for OSSA-2017-005 (CVE-2017-16239); however, only Nova stable/pike or later deployments with that fix applied and relying on the default FilterScheduler are affected.

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 16.0.3 (Pike), the default FilterScheduler fails to properly release hypervisor resources when an authenticated user repeatedly rebuilds an instance with new images. This causes untracked resource consumption leading to doubled resource allocations and eventual denial of service. The bug is a regression introduced by the fix for CVE-2017-16239.

MitigationOrganizations using Nova stable/pike with the default FilterScheduler should upgrade to patched versions or implement workarounds to ensure proper resource tracking during instance rebuild operations with new images.

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:= 16.0.3

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
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

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

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. Check Nova version
    Run 'nova-manage --version' or check the installed package version (e.g., 'rpm -q openstack-nova-common' or 'dpkg -l | grep nova')
    Affected if Version is exactly 16.0.3
  2. Verify FilterScheduler is in use
    Check the scheduler_driver setting in /etc/nova/nova.conf (or the equivalent config file). Look for 'scheduler_driver = nova.scheduler.filter_filter.FilterScheduler'
    Affected if FilterScheduler is configured as the default scheduler (this is the default setting)
  3. Confirm instance rebuild operations with new images
    Review Nova instance activity logs or use 'nova rebuild' commands with the '--image' flag to trigger rebuilds with different images
    Affected if Users are performing instance rebuild operations using different/new images, which triggers the flawed code path

A system is affected if it runs Nova version 16.0.3, uses the default FilterScheduler, and performs instance rebuild operations with new images, leading to unreleased hypervisor resources and doubled resource allocations.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Organizations using Nova stable/pike with the default FilterScheduler should upgrade to patched versions or implement workarounds to ensure proper resource tracking during instance rebuild operations with new images.

Fix this in Nova Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,580
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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-2017-17051 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
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