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LibvirtApplication · Redhat

CVE-2017-2635

MEDIUM · 6.5 CVSS v3.0 Published 2018-08-22
Fix available
A fix is available. Upgrade to after 3.0.0 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
A NULL pointer deference flaw was found in the way libvirt from 2.5.0 to 3.0.0 handled empty drives. A remote authenticated attacker could use this flaw to crash libvirtd daemon resulting in denial of service.

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

A NULL pointer dereference vulnerability in libvirt versions 2.5.0 through 3.0.0 exists when handling empty drives. An authenticated remote attacker can exploit this flaw to crash the libvirtd daemon, causing denial of service.

MitigationUpgrade libvirt to version 3.0.1 or later, which contains the fix for the NULL pointer dereference when processing empty drives.

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
Affected:>= 2.5.0, <= 3.0.0

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
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/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 installed libvirt version
    Run 'rpm -q libvirt' (RHEL) or 'dpkg -l libvirt-bin' (Debian) or 'libvirtd --version' to get the installed version number
    Affected if The version number is >= 2.5.0 and <= 3.0.0
  2. Verify libvirtd daemon is running
    Run 'systemctl status libvirtd' or 'ps aux | grep libvirtd' to confirm the daemon is active
    Affected if libvirtd is running and the version is in the affected range
  3. Check for empty drive configurations in domains
    Run 'virsh domblklist --all' to list block devices, then inspect each domain definition with 'virsh dumpxml <domain>' looking for <source dev=''/> or similar empty source attributes in disk devices
    Affected if Any domain has a disk device with an empty or missing source path
  4. Confirm remote authentication is enabled
    Check /etc/libvirt/libvirtd.conf for 'listen_tls' or 'auth_tcp' settings, and verify with 'virsh uri' showing a remote connection string
    Affected if Remote authentication (TCP/TLS) is enabled and the libvirtd is listening on network interfaces

The environment is affected if libvirtd is running with a version between 2.5.0 and 3.0.0, and there are domains configured with empty drives accessible to an authenticated remote attacker.

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 3.0.0
Interim mitigation

Upgrade libvirt to version 3.0.1 or later, which contains the fix for the NULL pointer dereference when processing empty drives.

Fix this in Libvirt Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing6.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,992.

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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-2017-2635 in production — separate from our analysis above.

No notes yet

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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
  • No spam, self-promotion, credentials, or personal data