LibvirtApplication · Redhat
CVE-2019-10166
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 · uneditedIt was discovered that libvirtd, versions 4.x.x before 4.10.1 and 5.x.x before 5.4.1, would permit readonly clients to use the virDomainManagedSaveDefineXML() API, which would permit them to modify managed save state files. If a managed save had already been created by a privileged user, a local attacker could modify this file such that libvirtd would execute an arbitrary program when the domain was resumed.
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 confidencelibvirtd versions 4.x.x before 4.10.1 and 5.x.x before 5.4.1 incorrectly permitted readonly clients to call the virDomainManagedSaveDefineXML() API, enabling modification of managed save state files. A local attacker with low privileges could inject arbitrary code into these files that would be executed by libvirtd when a domain is resumed from managed save state.
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
LibvirtApplication
>= 4.0.0, < 4.10.1>= 5.0.0, < 5.4.1
Enterprise LinuxOperating system
= 7.0= 8.0
Enterprise Linux DesktopOperating system
= 6.0= 7.0
Enterprise Linux ServerOperating system
= 6.0= 7.0
Enterprise Linux Server AusOperating system
= 7.6
Enterprise Linux Server EusOperating system
= 7.6
Enterprise Linux Server TusOperating system
= 7.6
Enterprise Linux WorkstationOperating system
= 6.0= 7.0CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
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Check installed libvirtd versionRun 'rpm -q libvirt' or 'libvirtd --version' to get the libvirt daemon version numberAffected if Version is 4.x.x before 4.10.1 or 5.x.x before 5.4.1 (for example 4.5.0, 5.2.0)
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Verify libvirtd service is runningRun 'systemctl status libvirtd' or check for the libvirtd process with 'ps aux | grep libvirtd'Affected if The libvirtd daemon is running and listening for client connections
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Check for existing managed save state filesList files in /var/lib/libvirt/qemu/save/ directory - these are .save files created by domain managed save operationsAffected if Any .save files exist in this directory, especially if created before applying the security update
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Verify client access permissions to libvirtd socketCheck the socket permissions at /var/run/libvirt/libvirt-sock and review /etc/libvirt/libvirtd.conf for auth_unix_ro settingAffected if The libvirtd socket is accessible to non-privileged users (default configuration allows this)
You are affected if running libvirtd version 4.0.0 to < 4.10.1 or 5.0.0 to < 5.4.1 and the service is accessible to low-privilege users who could call the virDomainManagedSaveDefineXML() API to modify managed save state files.
Generated from the published advisory. Verify against your own configuration.
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 data4.10.15.4.1
Upgrade libvirtd to version 4.10.1 or 5.4.1 or later. Additionally, audit existing managed save state files in /var/lib/libvirt/qemu/save/ for unauthorized modifications and remove any suspicious files before resuming domains.
Fix this in Libvirt
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-10166 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-10166 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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