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JunosOperating system · Juniper

CVE-2018-0055

MEDIUM · 5.3 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 →
58/100
Remediation priority · Elevated
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 specially crafted DHCPv6 message destined to a Junos OS device configured as a DHCP server in a Broadband Edge (BBE) environment may result in a jdhcpd daemon crash. The daemon automatically restarts without intervention, but a continuous receipt of crafted DHCPv6 packets could leaded to an extended denial of service condition. This issue only affects Junos OS 15.1 and later. Earlier releases are unaffected by this issue. Devices are only vulnerable to the specially crafted DHCPv6 message if DHCP services are configured. Devices not configured to act as a DHCP server are not vulnerable to this issue. Affected releases are Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S2; 15.1X49 versions prior to 15.1X49-D160; 15.1X53 versions prior to 15.1X53-D235, 15.1X53-D495; 16.1 versions prior to 16.1R4-S11, 16.1R6-S6, 16.1R7-S2; 16.2 versions prior to 16.2R2-S7; 17.1 versions prior to 17.1R2-S9; 17.2 versions prior to 17.2R2-S6; 17.3 versions prior to 17.3R3-S1; 17.4 versions prior to 17.4R1-S5; 18.1 versions prior to 18.1R2-S3; 18.2 versions prior to 18.2R1-S2; 18.2X75 versions prior to 18.2X75-D20.

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 specially crafted DHCPv6 packet sent to a Junos OS device configured as a DHCP server in a Broadband Edge (BBE) environment triggers a buffer overflow or parsing error in the jdhcpd daemon, causing it to crash. While the daemon auto-restarts, sustained malicious packets create a persistent denial of service. Devices without DHCP server configuration or not in BBE environments are not affected.

MitigationApply the vendor-supplied Junos OS patches corresponding to the affected version lines (15.1R7-S2, 15.1X49-D160, 15.1X53-D235/D495, 16.1R4-S11/16.1R6-S6/16.1R7-S2, 16.2R2-S7, 17.1R2-S9, 17.2R2-S6, 17.3R3-S1, 17.4R1-S5, 18.1R2-S3, 18.2R1-S2, 18.2X75-D20 or later). As an interim measure, disable DHCPv6 server services on impacted devices or restrict management plane access via firewall filters.

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= 18.2x75= 18.2

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/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' or 'show version detail' on the device and note the software version string
    Affected if The version matches one of the affected releases: 15.1, 15.1x49, 15.1x53, 16.1, 16.2, 17.1, 17.2, 17.3, 17.4, 18.2, or 18.2x75 series
  2. Verify DHCPv6 server configuration
    Run 'show configuration | match dhcp' or 'show configuration protocols dhcpv6' to inspect DHCP server settings
    Affected if DHCPv6 server service is explicitly configured on the device
  3. Confirm Broadband Edge context
    Review the device role and configuration context using 'show configuration system services dhcpv6' and check whether the device is deployed in a BBE/ broadband edge topology
    Affected if The device operates in a Broadband Edge (BBE) environment with DHCPv6 services enabled
  4. Monitor jdhcpd daemon stability
    Run 'show system processes extensive | match jdhcpd' or check system logs for daemon crash events
    Affected if The jdhcpd daemon is crashing repeatedly or showing instability

A device is affected if it runs an affected Junos version, has DHCPv6 server configured, and is deployed in a Broadband Edge environment, where specially crafted DHCPv6 packets can crash the jdhcpd daemon.

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 corresponding to the affected version lines (15.1R7-S2, 15.1X49-D160, 15.1X53-D235/D495, 16.1R4-S11/16.1R6-S6/16.1R7-S2, 16.2R2-S7, 17.1R2-S9, 17.2R2-S6, 17.3R3-S1, 17.4R1-S5, 18.1R2-S3, 18.2R1-S2, 18.2X75-D20 or later). As an interim measure, disable DHCPv6 server services on impacted devices or restrict management plane access via firewall filters.

Fix this in Junos Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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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-2018-0055 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data