FirepowerApplication · Cisco
CVE-2018-0272
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 Secure Sockets Layer (SSL) Engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper error handling while processing SSL traffic. An attacker could exploit this vulnerability by sending a large volume of crafted SSL traffic to the vulnerable device. A successful exploit could allow the attacker to degrade the device performance by triggering a persistent high CPU utilization condition. Cisco Bug IDs: CSCvh89340.
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 confidenceThis vulnerability exists in the SSL Engine of Cisco Firepower System Software due to improper error handling when processing SSL traffic. An unauthenticated remote attacker can exploit this by sending crafted SSL traffic, which triggers a persistent high CPU utilization condition and degrades device performance.
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
FirepowerApplication
= 6.2.1= 6.2.2.1CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/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 installed Cisco Firepower versionRun 'show version' or access the Firepower Management Center web UI to view the System > Updates page for the exact software versionAffected if The installed version is exactly 6.2.1 or 6.2.2.1
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Confirm SSL inspection is enabledCheck Firepower policy configuration: access the Firepower Management Center, navigate to Policies > Access Control, then inspect SSL/Decryption policy settings to verify SSL inspection is activeAffected if SSL inspection/decryption policies are enabled and the device is processing SSL traffic
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Monitor CPU utilization during SSL traffic processingUse 'show cpu' or Firepower Management Center health monitor to observe CPU usage patterns, particularly when SSL traffic flows through the deviceAffected if CPU utilization spikes persistently during SSL traffic processing
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Review SSL error logsCheck system logs via 'show log' or Firepower Management Center logging for SSL engine errors and warnings that may indicate malformed SSL traffic processing issuesAffected if Frequent SSL error messages appear in logs coinciding with high CPU events
You are affected if your Cisco Firepower System Software is version 6.2.1 or 6.2.2.1 and SSL inspection is enabled, causing high CPU when processing SSL 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 vendor patch from Cisco to address the vulnerability. If immediate patching is not possible, consider implementing rate limiting or filtering for suspicious SSL traffic at network perimeter devices.
Fix this in Firepower
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 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-2018-0272 — 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-2018-0272 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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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.
- 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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