Nx OsOperating system · Cisco
CVE-2018-0378
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 · uneditedA vulnerability in the Precision Time Protocol (PTP) feature of Cisco Nexus 5500, 5600, and 6000 Series Switches running Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a lack of protection against PTP frame flood attacks. An attacker could exploit this vulnerability by sending large streams of malicious IPv4 or IPv6 PTP traffic to the affected device. A successful exploit could allow the attacker to cause a DoS condition, impacting the traffic passing through the device.
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 confidenceA vulnerability in the Precision Time Protocol (PTP) implementation on Cisco Nexus 5500, 5600, and 6000 Series Switches allows an unauthenticated remote attacker to send large streams of malicious IPv4 or IPv6 PTP traffic, causing a denial of service condition that impacts all traffic passing through the affected device.
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
= 7.3\(2\)n1\(0.8\)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
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
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 the Nexus switch modelRun 'show version' or check the device model to confirm it is a Cisco Nexus 5500, 5600, or 6000 Series SwitchAffected if The device model is NOT one of these three series
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Check the NX-OS versionRun 'show version' and look for the software version. The affected version is exactly 7.3(2)n1(0.8)Affected if The NX-OS version is 7.3(2)n1(0.8)
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Verify if PTP is enabledRun 'show ptp' or 'show running-config | include ptp' to check if Precision Time Protocol is configured and active on the deviceAffected if PTP is enabled and running
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Assess network exposure to PTP trafficReview network topology and access controls to determine if untrusted IPv4 or IPv6 PTP traffic can reach the affected switch interfaceAffected if PTP traffic from untrusted sources can reach the device interfaces
A user is affected if they are running NX-OS version 7.3(2)n1(0.8) on a Nexus 5500, 5600, or 6000 Series Switch with PTP enabled and exposed to untrusted PTP 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 the Cisco software update when available. As a compensating control, disable PTP if not required, or implement network-edge filtering and rate-limiting on upstream switches/routers to block or limit PTP traffic before it reaches the affected devices.
Fix this in Nx Os
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-2018-0378 — 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-2018-0378 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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