dbcve.org
JunosOperating system · Juniper

CVE-2020-1664

HIGH · 7.8 CVSS v3.1 Published 2020-10-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
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
A stack buffer overflow vulnerability in the device control daemon (DCD) on Juniper Networks Junos OS allows a low privilege local user to create a Denial of Service (DoS) against the daemon or execute arbitrary code in the system with root privilege. This issue affects Juniper Networks Junos OS: 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.2X75 versions prior to 18.2X75-D53, 18.2X75-D65; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2. Versions of Junos OS prior to 17.3 are unaffected by this vulnerability.

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 stack buffer overflow vulnerability exists in the device control daemon (DCD) on Juniper Networks Junos OS. A low-privilege local user can trigger this overflow to cause denial of service against the DCD daemon or achieve arbitrary code execution with root privileges.

MitigationApply the vendor-supplied Junos OS software updates for the specific affected versions (17.3R3-S9, 17.4R2-S12/17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.2X75-D53/D65, 18.3R2-S4/18.3R3-S4, 18.4R2-S5/18.4R3-S5, 19.1R3-S3, 19.2R1-S5/19.2R3, 19.3R2-S4/19.3R3, 19.4R1-S3/19.4R2-S2/19.4R3, 20.1R1-S4/20.1R2, 20.2R1-S1/20.2R2 or later).

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:= 17.3= 17.4= 18.1= 18.2= 18.2x75= 18.3= 18.4= 19.1= 19.2= 19.3= 19.4= 20.1

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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. Identify the Junos OS version
    Execute 'show version' or 'request system version' on the device CLI to retrieve the installed Junos OS version number
    Affected if The displayed version matches one of the affected releases: 17.3, 17.4, 18.1, 18.2, 18.2x75, 18.3, 18.4, 19.1, 19.2, 19.3, 19.4, or 20.1
  2. Confirm the DCD daemon is running
    Execute 'show system processes daemon' or 'show system processes | match dcd' to verify the device control daemon (DCD) is active on the device
    Affected if The DCD daemon process is listed as running - the vulnerability is only exploitable when this daemon is active
  3. Check DCD configuration status
    Review the DCD configuration with 'show configuration | display set | match dcd' to see if device control interfaces are configured and active
    Affected if DCD has active interface configurations - the vulnerability requires DCD to be managing network interfaces for exploitation
  4. Verify if running a patched version
    Compare your installed version against the fixed releases: 17.3R3-S9, 17.4R2-S12/17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.2X75-D53/D65, 18.3R2-S4/18.3R3-S4, 18.4R2-S5/18.4R3-S5, 19.1R3-S3, 19.2R1-S5/19.2R3, 19.3R2-S4/19.3R3, 19.4R1-S3/19.4R2-S2/19.4R3, 20.1R1-S4/20.1R2, 20.2R1-S1/20.2R2 or later
    Affected if The installed version is earlier than any of these fixed versions and the DCD daemon is running

The environment is affected if the device runs Junos OS versions 17.3 through 20.1 with the DCD daemon active and the version is older than the vendor-supplied patched releases.

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

Apply the vendor-supplied Junos OS software updates for the specific affected versions (17.3R3-S9, 17.4R2-S12/17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.2X75-D53/D65, 18.3R2-S4/18.3R3-S4, 18.4R2-S5/18.4R3-S5, 19.1R3-S3, 19.2R1-S5/19.2R3, 19.3R2-S4/19.3R3, 19.4R1-S3/19.4R2-S2/19.4R3, 20.1R1-S4/20.1R2, 20.2R1-S1/20.2R2 or later).

Fix this in Junos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,968.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-1664 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-1664 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data