Cns Network RegistrarApplication · Cisco
CVE-2014-2155
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 DHCPv6 server module in Cisco CNS Network Registrar 7.1 allows remote attackers to cause a denial of service (daemon reload) via a malformed DHCPv6 packet, aka Bug ID CSCuo07437.
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 DHCPv6 server module in Cisco CNS Network Registrar 7.1 contains a vulnerability where processing malformed DHCPv6 packets triggers an uncontrolled daemon reload, causing denial of service. Attackers send specially crafted packets remotely without authentication, leading to service interruption.
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
Cns Network RegistrarApplication
= 7.1CVSS 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 CNS Network Registrar is installedLocate the installation directory or check installed software on the system. Typical locations may include /opt/cisco/ncn or C:\Program Files\Cisco\Network Registrar on Windows. Check for the 'nrnmd' or 'cnr' processes running.Affected if Cisco CNS Network Registrar software is present on the system
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Verify the installed version is 7.1Use the product's CLI interface (nrcmd) or check the version information via the administrative interface. Run 'nrcmd -N -C show version' or check the installed package version through the system package manager if available.Affected if The installed version equals exactly 7.1 (version 7.1 is the only affected version)
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Confirm DHCPv6 server module is enabledCheck the Cisco CNS Network Registrar configuration for DHCPv6 server settings. Use the nrcmd CLI with commands like 'dhcpv6 list' or 'dhcpv6 show' to determine if the DHCPv6 service is active and configured.Affected if DHCPv6 server is enabled and processing DHCPv6 requests
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Check for daemon crash or reload eventsReview system logs, Cisco CNS Network Registrar logs, or the Windows Event Log for entries indicating unexpected daemon reloads, crashes, or service interruptions. Look for patterns around DHCPv6 packet processing times.Affected if The daemon has crashed or reloaded unexpectedly, especially when processing DHCPv6 traffic
The environment is affected if Cisco CNS Network Registrar version 7.1 is installed with the DHCPv6 server module enabled and processing DHCPv6 traffic.
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 vendor-supplied patches for Cisco CNS Network Registrar 7.1 (Bug ID CSCuo07437). If no patch is available, consider network-level filtering of anomalous DHCPv6 traffic or disabling DHCPv6 if not required, until a fix is deployed.
Fix this in Cns Network Registrar
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 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-2014-2155 — 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-2014-2155 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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