CVE-2019-0005
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 · uneditedOn EX2300, EX3400, EX4600, QFX3K and QFX5K series, firewall filter configuration cannot perform packet matching on any IPv6 extension headers. This issue may allow IPv6 packets that should have been blocked to be forwarded. IPv4 packet filtering is unaffected by this vulnerability. Affected releases are Juniper Networks Junos OS on EX and QFX series;: 14.1X53 versions prior to 14.1X53-D47; 15.1 versions prior to 15.1R7; 15.1X53 versions prior to 15.1X53-D234 on QFX5200/QFX5110 series; 15.1X53 versions prior to 15.1X53-D591 on EX2300/EX3400 series; 16.1 versions prior to 16.1R7; 17.1 versions prior to 17.1R2-S10, 17.1R3; 17.2 versions prior to 17.2R3; 17.3 versions prior to 17.3R3; 17.4 versions prior to 17.4R2; 18.1 versions prior to 18.1R2.
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 confidenceOn EX2300, EX3400, EX4600, QFX3K and QFX5K series devices, firewall filter configuration cannot perform packet matching on IPv6 extension headers. This allows IPv6 packets that should have been blocked by filter rules to be forwarded through the device, while IPv4 packet filtering remains unaffected.
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= 14.1x53= 15.1= 15.1x53= 16.1= 17.1= 17.2= 17.3= 17.4= 18.1CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify device modelRun 'show chassis hardware' or check physical labeling to confirm the device is an EX2300, EX3400, EX4600, QFX3K, or QFX5K series switchAffected if device model is NOT one of these series
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Check Junos OS versionRun 'show version' and note the Junos software version installedAffected if version is 14.1x53, 15.1, 15.1x53, 16.1, 17.1, 17.2, 17.3, 17.4, or 18.1 (base releases before patches)
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Verify IPv6 firewall filter configurationRun 'show configuration firewall' and look for filter terms applied to IPv6 interfaces or family inet6 blocksAffected if no IPv6 firewall filters are configured
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Confirm IPv6 traffic with extension headers existsMonitor traffic with 'show interfaces' statistics or capture packets to identify IPv6 traffic with extension headers (fragmentation, routing, hop-by-hop, destination options)Affected if no IPv6 extension header traffic is passing through the device
You are affected if your device is an EX2300/EX3400/EX4600/QFX3K/QFX5K running an unpatched Junos version (14.1x53 through 18.1) AND you have IPv6 firewall filters applied that should match on IPv6 extension headers.
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 appropriate Junos OS software update from the patched versions listed (14.1X53-D47, 15.1R7, 15.1X53-D234/D591, 16.1R7, 17.1R3/2-S10, 17.2R3, 17.3R3, 17.4R2, or 18.1R2 depending on platform).
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-0005 — 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-2019-0005 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
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