Nx OsOperating system · Cisco
CVE-2013-1213
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 · uneditedCisco NX-OS on the Nexus 1000V does not assign the proper priority to heartbeat messages from a Virtual Ethernet Module (VEM) to a Virtual Supervisor Module (VSM), which allows remote attackers to cause a denial of service (false VEM unavailability report) via a flood of UDP packets, aka Bug ID CSCud14840.
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 · moderate confidenceIn Cisco NX-OS on Nexus 1000V, heartbeat messages from Virtual Ethernet Modules (VEM) to the Virtual Supervisor Module (VSM) are not assigned proper priority. This allows remote attackers to flood the network with UDP packets, which disrupts the heartbeat mechanism and causes false VEM unavailability reports, resulting in a denial of service condition.
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
Nx OsOperating system
all versions
Nexus 1000vHardware / appliance
all versionsCVSS 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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Identify if Cisco NX-OS is runningRun 'show version' on the device and look for 'Cisco NX-OS' in the outputAffected if The device is running any version of Cisco NX-OS with the VEM-to-VSM heartbeat mechanism active
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Identify if Cisco Nexus 1000V is deployedRun 'show module' to list all modules in the systemAffected if Any Virtual Ethernet Modules (VEM) and Virtual Supervisor Module (VSM) are present in the output
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Confirm VEM-to-VSM heartbeat is activeRun 'show vem heartbeat' or 'show module vem' to check the heartbeat status between VEM and VSMAffected if Heartbeat is enabled and VEM modules are attempting to communicate with the VSM
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Check if VSM management interface accepts UDP trafficRun 'show interface vsm-mgmt' or similar command to verify the VSM management interface configuration and its accessibilityAffected if The VSM management interface is reachable and accepts UDP packets on the heartbeat port
If the environment runs Cisco NX-OS or Cisco Nexus 1000V with VEM and VSM modules and the heartbeat mechanism is active, the system is affected by this vulnerability because all versions lack proper priority handling for VEM-to-VSM heartbeat messages.
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 relevant Cisco patch for bug CSCud14840, which provides proper priority handling for VEM-to-VSM heartbeat messages. Consider implementing network segmentation or rate limiting on UDP traffic to the VSM management interface as an interim measure.
Fix this in Nx Os
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-1213 — 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-2013-1213 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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