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JunosOperating system · Juniper

CVE-2020-1605

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 IPv4 packets who may then arbitrarily execute commands as root on the target device. This issue affects IPv4 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

JDHCPD in relay mode on Junos OS/Evolved has a remote code execution vulnerability. Attackers can send crafted IPv4 packets to the DHCP relay service to execute arbitrary commands as root on the affected device.

MitigationUpgrade Junos OS to a fixed version (15.1R7-S6, 16.1R7-S6, 17.1R3-S1, 17.2R3-S3, 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 Junos OS Evolved 19.3R1+). Alternatively, disable DHCP relay mode and use local server mode if upgrade is not feasible.

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 Junos OS version
    Run 'show version' or 'system: show version' command on the device to obtain the installed Junos OS version
    Affected if The installed version matches one of the affected versions: 15.1, 15.1x49, 15.1x53, 16.1, 16.2, 17.1, 17.2, 17.3, 17.4, 18.1, 18.2, or 18.2x75
  2. Verify DHCP relay is enabled
    Run 'show configuration system services dhcp-relay' to view the DHCP relay configuration
    Affected if DHCP relay is configured and active (the 'dhcp-relay' stanza exists under 'system services')
  3. Confirm relay mode configuration
    Run 'show configuration system services dhcp-relay' and look for active relay configuration including 'server' or 'bulk-leasequery' statements under the relay configuration
    Affected if The device is operating in DHCP relay mode (not local server mode)

The device is affected if it runs a vulnerable Junos OS version (15.1 through 18.2x75) AND has DHCP relay mode enabled and configured.

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 a fixed version (15.1R7-S6, 16.1R7-S6, 17.1R3-S1, 17.2R3-S3, 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 Junos OS Evolved 19.3R1+). Alternatively, disable DHCP relay mode and use local server mode if upgrade is not feasible.

Fix this in Junos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
24.0 hours of engineering $4,200
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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-2020-1605 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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