LibvirtApplication · Redhat
CVE-2012-4423
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 virNetServerProgramDispatchCall function in libvirt before 0.10.2 allows remote attackers to cause a denial of service (NULL pointer dereference and segmentation fault) via an RPC call with (1) an event as the RPC number or (2) an RPC number whose value is in a "gap" in the RPC dispatch table.
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 confidenceThe virNetServerProgramDispatchCall function in libvirt before 0.10.2 lacks proper validation of RPC numbers, allowing remote attackers to trigger a NULL pointer dereference by sending RPC calls with either an event RPC number or a value falling within gaps in the RPC dispatch table, resulting in a segmentation fault and denial of service.
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
<= 0.10.1= 0.0.1= 0.0.2= 0.0.3= 0.0.4= 0.0.5= 0.0.6= 0.1.0= 0.1.1= 0.1.3= 0.1.4= 0.1.5CVSS 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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/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.
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Check if libvirt is installedRun 'rpm -qa | grep libvirt' on Red Hat-based systems, or check for libvirt packages on other distributions using your package managerAffected if libvirt package is present on the system
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Determine installed libvirt versionRun 'rpm -q libvirt' or 'libvirtd --version' to get the exact version numberAffected if version is 0.10.1 or earlier, or matches one of the specific vulnerable versions (0.0.1, 0.0.2, 0.0.3, 0.0.4, 0.0.5, 0.0.6, 0.1.0, 0.1.1, 0.1.3, 0.1.4, 0.1.5)
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Verify libvirtd is listening on the networkRun 'netstat -tlnp | grep libvirtd' or 'ss -tlnp | grep libvirtd' to see if the service is bound to network interfacesAffected if libvirtd is listening on TCP ports (typically 16509) or other network interfaces, exposing the RPC service to remote connections
A system is affected if it runs a vulnerable libvirt version (0.10.1 or earlier) AND has libvirtd exposed to network access, allowing remote attackers to trigger the NULL pointer dereference via crafted RPC calls
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 0.10.2 or later which contains the fix for proper RPC number validation. As a secondary measure, restrict network access to libvirtd to trusted clients only.
Fix this in Libvirt
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-4423 — 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-2012-4423 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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