CVE-2014-3814: The Juniper Networks NetScreen Firewall devices with ScreenOS before 6.3r17, when configured to use the intern

Q: How do I fix CVE-2014-3814?

screenos: upgrade to newer than 6.3.0; netscreen-5200: mitigate or apply the listed mitigation; netscreen-5400: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2014-3814 being exploited?

CVE-2014-3814 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2014-3814 affect?

CVE-2014-3814 affects screenos, netscreen-5200, netscreen-5400. Severity is high (CVSS 7.8). The Juniper Networks NetScreen Firewall devices with ScreenOS before 6.3r17, when configured to use the internal DNS lookup client, allows remote attackers to cause a denial of service (crash and reboot) via a sequence of malformed packets

This month

HIGH 7.8UPGRADEMITIGATEMITIGATE

CVE-2014-3814 is a high-severity flaw (CVSS 7.8) affecting screenos, netscreen-5200, netscreen-5400. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Juniper Networks NetScreen Firewall devices with ScreenOS before 6.3r17, when configured to use the internal DNS lookup client, allows remote attackers to cause a denial of service (crash and reboot) via a sequence of malformed packets to the device IP.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
EPSS exploit chance	1.3% (top 29%)
CISA exploited list	No
Weakness	CWE-20
Published	2014-06-13
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: juniper

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2014-06-13 14:55 UTCPublished CVE record published
2026-06-17 00:08 UTCUpdated Record last modified

juniper screenos UPGRADE

Affected: <= 6.3.0 · 6.0.0 · 6.1.0 · 6.2.0

Fixed in: newer than 6.3.0

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

juniper netscreen-5200 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Firmware

Install the latest firmware from the vendor advisory; if none, apply the vendor workaround.

juniper netscreen-5400 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Firmware

Install the latest firmware from the vendor advisory; if none, apply the vendor workaround.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2014-3814?

screenos: upgrade to newer than 6.3.0; netscreen-5200: mitigate or apply the listed mitigation; netscreen-5400: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2014-3814 being exploited?

CVE-2014-3814 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2014-3814 affect?

CVE-2014-3814 affects screenos, netscreen-5200, netscreen-5400. Severity is high (CVSS 7.8). The Juniper Networks NetScreen Firewall devices with ScreenOS before 6.3r17, when configured to use the internal DNS lookup client, allows remote attackers to cause a denial of service (crash and reboot) via a sequence of malformed packets

How urgent is CVE-2014-3814?

Priority 45/100. High severity

Software pages

Juniper Junos vulnerabilities

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References

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