JunosOperating system · Juniper

CVE-2018-0043

HIGH · 8.8 CVSS v3.0 Published 2018-10-10
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
Receipt of a specific MPLS packet may cause the routing protocol daemon (RPD) process to crash and restart or may lead to remote code execution. By continuously sending specific MPLS packets, an attacker can repeatedly crash the RPD process causing a sustained Denial of Service. This issue affects both IPv4 and IPv6. This issue can only be exploited from within the MPLS domain. End-users connected to the CE device cannot cause this crash. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D77 on SRX Series; 12.3 versions prior to 12.3R12-S10; 12.3X48 versions prior to 12.3X48-D75 on SRX Series; 14.1X53 versions prior to 14.1X53-D47 on QFX/EX Series; 14.1X53 versions prior to 14.1X53-D130 on QFabric Series; 15.1F6 versions prior to 15.1F6-S10; 15.1 versions prior to 15.1R4-S9 15.1R7; 15.1X49 versions prior to 15.1X49-D140 on SRX Series; 15.1X53 versions prior to 15.1X53-D59 on EX2300/EX3400 Series; 15.1X53 versions prior to 15.1X53-D67 on QFX10K Series; 15.1X53 versions prior to 15.1X53-D233 on QFX5200/QFX5110 Series; 15.1X53 versions prior to 15.1X53-D471 15.1X53-D490 on NFX Series; 16.1 versions prior to 16.1R3-S8 16.1R4-S8 16.1R5-S4 16.1R6-S4 16.1R7; 16.1X65 versions prior to 16.1X65-D48; 16.2 versions prior to 16.2R1-S6 16.2R3; 17.1 versions prior to 17.1R1-S7 17.1R2-S6 17.1R3; 17.2 versions prior to 17.2R1-S6 17.2R2-S3 17.2R3; 17.2X75 versions prior to 17.2X75-D100 17.2X75-D42 17.2X75-D91; 17.3 versions prior to 17.3R1-S4 17.3R2-S2 17.3R3; 17.4 versions prior to 17.4R1-S3 17.4R2 . No other Juniper Networks products or platforms are affected by this issue.

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 specifically crafted MPLS packet triggers a critical vulnerability in the Junos OS routing protocol daemon (RPD). When received, the packet causes RPD to crash and restart, leading to potential remote code execution. An attacker within the MPLS domain can exploit this repeatedly to cause sustained denial of service, affecting both IPv4 and IPv6 traffic flows.

MitigationApply the vendor-supplied Junos OS patches for affected versions (12.1X46-D77, 12.3R12-S10, 12.3X48-D75, etc.) during a maintenance window. As an interim control, implement strict MPLS packet filtering at domain boundaries to block untrusted MPLS 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
JunosOperating system
Affected:= 12.1x46= 12.3= 12.3x48= 14.1x53= 15.1= 15.1x49= 15.1x53= 16.1= 16.1x65= 16.2= 17.1= 17.2x75

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:3.0/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. Identify the Junos OS version
    Run 'show version' command on the device CLI to obtain the installed Junos OS version number
    Affected if The version matches one of these affected releases: 12.1X46, 12.3, 12.3X48, 14.1X53, 15.1, 15.1X49, 15.1X53, 16.1, 16.1X65, 16.2, 17.1, or 17.2X75 (or falls within any unpatched range of these branches)
  2. Verify if MPLS is enabled
    Run 'show configuration protocols mpls' to check if MPLS protocol is configured on the device
    Affected if MPLS protocol is actively configured or enabled on any interface
  3. Confirm MPLS interface exposure
    Run 'show mpls interface' to list all interfaces with MPLS enabled, then review whether these interfaces accept traffic from untrusted sources
    Affected if MPLS interfaces are connected to external or untrusted MPLS domains where malicious packets could be injected
  4. Check for RPD crash history
    Run 'show log messages | match rpd' and 'show system core-dumps' to examine if RPD has recently crashed or restarted
    Affected if RPD crash events correlate with MPLS traffic receipt from untrusted sources (note: crashes may have other causes)

A device is affected if it runs a vulnerable Junos version (12.1X46 through 17.2X75 unpatched) AND has MPLS enabled on interfaces exposed to untrusted MPLS traffic sources.

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 patches for affected versions (12.1X46-D77, 12.3R12-S10, 12.3X48-D75, etc.) during a maintenance window. As an interim control, implement strict MPLS packet filtering at domain boundaries to block untrusted MPLS traffic.

Fix this in Junos Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,980
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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-2018-0043 in production — separate from our analysis above.

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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
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