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JunosOperating system · Juniper

CVE-2020-1609

HIGH · 8.8 CVSS v3.1 Published 2020-01-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
93/100
Remediation priority · Urgent
No privileges Zero-click

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 · unedited
When a device using Juniper Network's Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv6 packets who may then arbitrarily execute commands as root on the target device. This issue affects IPv6 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.

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 confidence

A command injection vulnerability exists in the Juniper JDHCPD daemon when configured in IPv6 relay mode on Junos OS and Junos OS Evolved. An unauthenticated remote attacker can send specially crafted IPv6 packets to execute arbitrary commands with root privileges on the affected device.

MitigationUpgrade Junos OS to one of the listed fixed versions (15.1R7-S6, 15.1X49-D200, 16.1R7-S6, 17.1R2-S11, 17.2R2-S8, 17.3R3-S6, 17.4R2-S7, 18.1R3-S8, 18.2R3-S2, 18.2X75-D60, 18.3R3, 18.4R3, 19.1R2, 19.2R2, or 19.3R1 or later). If upgrading is not immediately feasible, disable IPv6 JDHCPD relay functionality as a compensating control.

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
JunosOperating system
Affected:= 15.1= 15.1x49= 15.1x53= 16.1= 16.2= 17.1= 17.2= 17.3= 17.4= 18.1= 18.2= 18.2x75

CVSS 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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check the Junos OS version
    Run 'show version' on the device CLI and compare the installed version against the affected ranges: 15.1, 15.1x49, 15.1x53, 16.1, 16.2, 17.1, 17.2, 17.3, 17.4, 18.1, 18.2, 18.2x75
    Affected if The device runs any of the listed version numbers exactly as specified in the affected versions list
  2. Verify JDHCPD daemon is configured
    Check the Junos configuration for DHCPv6 relay agent settings using 'show configuration | match jdhcpd' or review the system services dhcpv6 relay configuration
    Affected if JDHCPD daemon is configured and active on the device
  3. Confirm IPv6 relay mode is enabled
    Examine the DHCPv6 relay configuration with 'show configuration forwarding-options helpers dhcpv6' or 'show configuration services dhcpv6 relay' to determine if IPv6 relay functionality is enabled
    Affected if IPv6 relay mode is explicitly configured and enabled in the DHCPv6 relay settings
  4. Check for IPv6 interface bindings
    Review 'show dhcpv6 relay bindings' or 'show interfaces' with IPv6 addresses to identify which interfaces have IPv6 configured and are bound to the relay service
    Affected if IPv6 is active on interfaces and the JDHCPD relay is bound to process IPv6 traffic

The device is affected only if it runs an affected Junos version AND has IPv6 relay mode actively configured for the JDHCPD daemon, which enables the command injection attack surface.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Junos OS to one of the listed fixed versions (15.1R7-S6, 15.1X49-D200, 16.1R7-S6, 17.1R2-S11, 17.2R2-S8, 17.3R3-S6, 17.4R2-S7, 18.1R3-S8, 18.2R3-S2, 18.2X75-D60, 18.3R3, 18.4R3, 19.1R2, 19.2R2, or 19.3R1 or later). If upgrading is not immediately feasible, disable IPv6 JDHCPD relay functionality as a compensating control.

Fix this in Junos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
25.0 hours of engineering $4,400
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-1609 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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