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JunosOperating system · Juniper

CVE-2020-1678

MEDIUM · 6.5 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 →
70/100
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
On Juniper Networks Junos OS and Junos OS Evolved platforms with EVPN configured, receipt of specific BGP packets causes a slow memory leak. If the memory is exhausted the rpd process might crash. If the issue occurs, the memory leak could be seen by executing the "show task memory detail | match policy | match evpn" command multiple times to check if memory (Alloc Blocks value) is increasing. root@device> show task memory detail | match policy | match evpn ------------------------ Allocator Memory Report ------------------------ Name | Size | Alloc DTXP Size | Alloc Blocks | Alloc Bytes | MaxAlloc Blocks | MaxAlloc Bytes Policy EVPN Params 20 24 3330678 79936272 3330678 79936272 root@device> show task memory detail | match policy | match evpn ------------------------ Allocator Memory Report ------------------------ Name | Size | Alloc DTXP Size | Alloc Blocks | Alloc Bytes | MaxAlloc Blocks | MaxAlloc Bytes Policy EVPN Params 20 24 36620255 878886120 36620255 878886120 This issue affects: Juniper Networks Junos OS 19.4 versions prior to 19.4R2; 20.1 versions prior to 20.1R1-S4, 20.1R2; Juniper Networks Junos OS Evolved: 19.4 versions; 20.1 versions prior to 20.1R1-S4-EVO, 20.1R2-EVO; 20.2 versions prior to 20.2R1-EVO; This issue does not affect: Juniper Networks Junos OS releases prior to 19.4R1. Juniper Networks Junos OS Evolved releases prior to 19.4R1-EVO.

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 memory leak vulnerability exists in Juniper Networks Junos OS and Junos OS Evolved with EVPN configured. When specific BGP packets are received, the rpd (routing process daemon) experiences a slow memory leak in the Policy EVPN Params allocator. If left unaddressed and memory is exhausted, the rpd process will crash, causing network disruption. The memory leak can be observed by monitoring the 'Alloc Blocks' value in the 'show task memory detail | match policy | match evpn' command output over time.

MitigationApply the appropriate Juniper software update for your version (19.4R2+, 20.1R1-S4/20.1R2+, or 20.2R1-EVO+) to address the vulnerability. Monitor memory usage using the documented command and consider implementing BGP route filtering or packet filters as a temporary mitigation until the patch can be applied.

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:= 19.4= 20.1
Junos Os EvolvedOperating system
Affected:= 19.4= 20.1= 20.2

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

CVSS:3.1/AV:A/AC:L/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. Check Junos version
    Run 'show version' or 'show version detail' to identify the installed Junos OS version
    Affected if Version is 19.4 (any release) or 20.1 (any release) or 20.2 (any release) for Junos OS Evolved. For standard Junos OS, version is 19.4 or 20.1 (any release).
  2. Confirm EVPN configuration
    Run 'show configuration protocols evpn' or 'show configuration | match evpn' to check if EVPN is configured on the device
    Affected if EVPN protocol is configured and active.
  3. Monitor Policy EVPN Params allocator memory
    Run 'show task memory detail | match policy | match evpn' and observe the 'Alloc Blocks' value. Repeat this command over several minutes or hours to detect an increasing trend in the Alloc Blocks value.
    Affected if The Alloc Blocks value increases consistently over time, indicating a memory leak in the Policy EVPN Params allocator.

The device is affected if it runs a vulnerable Junos OS version (19.4, 20.1, or 20.2 for Evolved), has EVPN configured, and shows a rising Alloc Blocks count in the Policy EVPN Params allocator when monitored over time.

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 appropriate Juniper software update for your version (19.4R2+, 20.1R1-S4/20.1R2+, or 20.2R1-EVO+) to address the vulnerability. Monitor memory usage using the documented command and consider implementing BGP route filtering or packet filters as a temporary mitigation until the patch can be applied.

Fix this in Junos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2020-1678 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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