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Nx OsOperating system · Cisco

CVE-2013-1209

MEDIUM · 5.0 CVSS v2.0 Published 2013-05-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable No privileges 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
The encryption functionality in the Virtual Supervisor Module (VSM) to Virtual Ethernet Module (VEM) communication component in Cisco NX-OS on the Nexus 1000V does not properly authenticate VSM/VEM packets, which allows remote attackers to disable packet-level encryption and integrity protection via crafted packets, aka Bug ID CSCud14710.

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

The encryption functionality in Cisco NX-OS for Nexus 1000V's VSM-to-VEM communication lacks proper packet authentication, allowing remote attackers to send crafted packets that disable packet-level encryption and integrity protection. This is a security downgrade attack where the lack of authentication on the encryption control plane permits attackers to force the system into an insecure mode.

MitigationApply the relevant Cisco NX-OS patch for Bug ID CSCud14710. As a compensating control, restrict network access to the VSM/VEM communication paths to prevent unauthorized attackers from sending crafted packets.

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
Affected:all versions

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
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None

AV:N/AC:L/Au:N/C:N/I:P/A:N

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. Confirm Nexus 1000V is deployed
    Run 'show module' or 'show version' on the device to verify the presence of Nexus 1000V Virtual Supervisor Module (VSM) and Virtual Ethernet Modules (VEM)
    Affected if The device is running Nexus 1000V with VSM and VEM components present
  2. Check VSM-to-VEM encryption status
    Run 'show vem feature' or 'show system internal vem-mgr vemnem' to verify if packet-level encryption and integrity protection are enabled for VSM-VEM communication
    Affected if Encryption and integrity protection are disabled or not configured for VSM-VEM traffic
  3. Verify encryption control plane is authenticated
    Review the VSM-VEM communication configuration using 'show running-config' and look for any authentication or key configuration for the control plane
    Affected if No packet authentication is configured on the encryption control plane between VSM and VEM
  4. Check for signs of downgrade or insecure mode
    Review system logs using 'show logging' for any messages indicating encryption was disabled, downgraded, or that control plane authentication failures occurred
    Affected if Logs show encryption being disabled or control plane messages indicating security mode changes
  5. Review network access to VSM-VEM paths
    Inspect access control lists and interface configurations to determine if the VSM-VEM communication paths are exposed to untrusted networks
    Affected if VSM-VEM communication paths are accessible from untrusted or management networks without proper segmentation

A user is affected if they run Nexus 1000V with VSM-VEM encryption disabled, lacking packet authentication on the encryption control plane, or if the VSM-VEM paths are accessible to untrusted attackers who could send crafted packets to force an insecure mode.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant Cisco NX-OS patch for Bug ID CSCud14710. As a compensating control, restrict network access to the VSM/VEM communication paths to prevent unauthorized attackers from sending crafted packets.

Fix this in Nx Os Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2013-1209 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