CVE-2017-2304
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 · uneditedJuniper Networks QFX3500, QFX3600, QFX5100, QFX5200, EX4300 and EX4600 devices running Junos OS 14.1X53 prior to 14.1X53-D40, 15.1X53 prior to 15.1X53-D40, 15.1 prior to 15.1R2, do not pad Ethernet packets with zeros, and thus some packets can contain fragments of system memory or data from previous packets. This issue is also known as 'Etherleak'
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 confidenceJuniper switches and EX series devices fail to zero-pad Ethernet frames to meet the minimum 64-byte frame size requirement, causing fragments of system memory or previous packet data to be transmitted in outbound packets. This information disclosure vulnerability (Etherleak) allows potentially sensitive data to leak via network traffic.
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= 15.1x53CVSS 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
- High
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 the device modelRun 'show chassis hardware' or check the physical label to confirm this is a Juniper switch or EX series deviceAffected if Device is a Juniper switch or EX series model
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Determine the Junos OS versionRun 'show version' or 'request version' command to retrieve the installed Junos versionAffected if Version shows 14.1x53, 15.1, or 15.1x53 without the D40 or R2 patch variants
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Compare version to affected rangesReview the full version string (for example, 14.1X53-D30 or 15.1R1 would be affected; 14.1X53-D40, 15.1X53-D40, or 15.1R2 and later are fixed)Affected if Version matches 14.1x53, 15.1, or 15.1x53 and lacks the D40 or R2 patch updates
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Verify network traffic is being transmittedRun 'show interfaces' or monitor traffic on active network portsAffected if The device has active network interfaces transmitting traffic (vulnerability only affects outbound packets)
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Capture outbound packets to inspect for data leakageUse a packet sniffer on an outbound port to capture frames smaller than 64 bytes and examine payload for non-padded data or memory fragmentsAffected if Outbound Ethernet frames under 64 bytes contain unexpected data rather than zero-padding
If the device runs Junos 14.1x53, 15.1, or 15.1x53 without the D40 or R2 patches and is actively transmitting network traffic, it is likely affected by the Etherleak information disclosure vulnerability.
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 Junos OS to version 14.1X53-D40, 15.1X53-D40, 15.1R2 or later to remediate the unpadded Ethernet frame issue.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-2304 — 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-2017-2304 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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