Ubuntu LinuxOperating system · Canonical
CVE-2014-3633
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 · uneditedThe qemuDomainGetBlockIoTune function in qemu/qemu_driver.c in libvirt before 1.2.9, when a disk has been hot-plugged or removed from the live image, allows remote attackers to cause a denial of service (crash) or read sensitive heap information via a crafted blkiotune query, which triggers an out-of-bounds read.
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 confidenceA flaw in libvirt's qemuDomainGetBlockIoTune function allows out-of-bounds heap reads when processing a crafted blkiotune query after a disk has been hot-plugged or removed from a live guest image. Remote attackers can trigger this to crash the libvirtd daemon (denial of service) or potentially leak sensitive heap memory contents.
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
Ubuntu LinuxOperating system
= 10.04= 12.04= 14.04<= 1.2.8= 1.2.0= 1.2.1= 1.2.2= 1.2.3= 1.2.4= 1.2.5= 1.2.6= 1.2.7CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- None
- Availability
- Partial
AV:N/AC:M/Au:N/C:P/I:N/A:P
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.
-
Identify installed libvirt versionRun 'virsh --version' or 'rpm -q libvirt' (RHEL) or 'dpkg -l libvirt-bin' (Debian/Ubuntu)Affected if Version is 1.2.8 or lower, or on Ubuntu 10.04/12.04/14.04 with libvirt <= 1.2.8
-
Verify libvirtd daemon is runningRun 'service libvirtd status' or 'systemctl status libvirtd'Affected if Libvirtd is active and the version is in the affected range above
-
Check for active VMs with disk devicesRun 'virsh list --all' to list all VMs, then 'virsh dumpxml <domain>' to inspect disk configurationAffected if Any VM has disks attached, as the flaw triggers after disk hot-plug or removal operations
-
Monitor for recent disk hot-plug or removal operationsReview libvirtd logs (typically /var/log/libvirt/libvirtd.log or journalctl -u libvirtd) for 'hotplug' or 'detach' events related to disk devicesAffected if Disk hot-plug or removal has occurred on any running VM since libvirtd started
-
Inspect blkiotune query accessibilityRun 'virsh blkiotune <domain>' on any active VM to test if the function is reachableAffected if The command executes without error and returns block I/O tuning information
A system is likely affected if it runs a vulnerable libvirt version (1.2.8 or earlier) with active VMs that have undergone disk hot-plug or removal operations, and the blkiotune query function is accessible.
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 dataUpgrade libvirt to version 1.2.9 or later. If upgrading is not immediately possible, restrict remote management access to trusted users and monitor for unusual blkiotune queries.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 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 $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2014-3633 — 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-2014-3633 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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