Debian LinuxOperating system · Debian
CVE-2013-4494
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 · uneditedXen before 4.1.x, 4.2.x, and 4.3.x does not take the page_alloc_lock and grant_table.lock in the same order, which allows local guest administrators with access to multiple vcpus to cause a denial of service (host deadlock) via unspecified vectors.
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 confidenceXen hypervisor before 4.1.x, 4.2.x, and 4.3.x has a lock ordering bug where page_alloc_lock and grant_table.lock are acquired in inconsistent orders across different code paths. A malicious local guest administrator with access to multiple vCPUs can trigger a deadlock condition by exploiting this lock inversion, causing the host to become unresponsive.
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
Debian LinuxOperating system
= 7.0>= 4.1.0, <= 4.1.6.1>= 4.2.0, <= 4.2.5>= 4.3.0, <= 4.3.4CVSS 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
- Adjacent
- Complexity
- M
- Authentication
- Single
- Confidentiality
- None
- Integrity
- None
- Availability
- Complete
AV:A/AC:M/Au:S/C:N/I:N/A:C
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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Determine the Xen hypervisor versionRun `xl version` or `xm version` from dom0, or check the package version with `dpkg -l | grep xen-hypervisor` on DebianAffected if The version is 4.1.0-4.1.6.1, 4.2.0-4.2.5, or 4.3.0-4.3.4
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Verify the host kernel is a Xen kernelRun `uname -a` and confirm the kernel name includes 'xen' or check `/boot/` for xen-dom0 kernel imagesAffected if Running a Xen hypervisor host (dom0) with a vulnerable Xen version from step 1
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Check if any guest domains have multiple vCPUs assignedRun `xl list` or `xm list` to view running domains and their vCPU countsAffected if A guest domain has 2 or more vCPUs, which is required for a malicious guest administrator to trigger the deadlock
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Check if grant tables are in active useInspect guest configuration files in /etc/xen/ for 'grant_table' settings or PCI passthrough devices that use grant tables, or run `xl pci-list <guest>`Affected if The Xen hypervisor version is 4.1.0 through 4.1.6.1, 4.2.0 through 4.2.5, or 4.3.0 through 4.3.4
You are affected if your Xen hypervisor version falls within the listed vulnerable ranges and you run guest domains with multiple vCPUs and grant table access.
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 dataApply the vendor patch or upgrade Xen to version 4.1.x, 4.2.x, or 4.3.x (or later) that implements consistent lock ordering between page_alloc_lock and grant_table.lock.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation8.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,304.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-4494 — 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-2013-4494 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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- 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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