Ios XeOperating system · Cisco
CVE-2018-0471
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 Cisco Discovery Protocol (CDP) module of Cisco IOS XE Software Releases 16.6.1 and 16.6.2 could allow an unauthenticated, adjacent attacker to cause a memory leak that may lead to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain CDP packets. An attacker could exploit this vulnerability by sending certain CDP packets to an affected device. A successful exploit could cause an affected device to continuously consume memory and eventually result in a memory allocation failure that leads to a crash, triggering a reload of the affected 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 memory leak vulnerability in the Cisco Discovery Protocol (CDP) module of Cisco IOS XE versions 16.6.1 and 16.6.2 allows an unauthenticated adjacent attacker to send specially crafted CDP packets that cause improper memory handling, leading to progressive memory exhaustion and eventual device crash/DoS.
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
Ios XeOperating system
= 16.6.1= 16.6.2CVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:A/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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Check the IOS XE versionRun 'show version' on the device and locate the version string in the outputAffected if The version shown is exactly 16.6.1 or 16.6.2
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Verify CDP is enabled globallyRun 'show cdp' or 'show cdp neighbor' and confirm the output shows CDP is runningAffected if CDP is enabled and running on the device (the vulnerability requires CDP to be active)
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Confirm CDP interface statusRun 'show cdp interface' to list interfaces where CDP is currently enabledAffected if Any interface has CDP enabled (vulnerable to adjacent network attackers)
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Assess adjacent network accessibilityReview network topology to determine if untrusted devices can reach the device's CDP-enabled interfaces (same L2 segment)Affected if Untrusted adjacent attackers can directly send packets to the device (CDP is a link-layer protocol)
The device is affected if it runs IOS XE version 16.6.1 or 16.6.2 AND has CDP enabled on at least one interface AND is accessible to adjacent attackers on that segment.
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 Cisco IOS XE to version 16.6.3 or later. If immediate upgrade is not feasible, consider disabling CDP on untrusted interfaces or implementing network segmentation to limit adjacent attacker access.
Fix this in Ios Xe
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-2018-0471 — 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-2018-0471 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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