CVE-2020-1604Network attack vector

Firewall bypass via failed packet filter evaluation

Published Jan 15, 2020 · Updated Sep 16, 2024

Improper access control in Junos OS on EX/QFX switches allows remote attackers to bypass Routing Engine firewall filtering. The stateless IP firewall filter fails to evaluate certain IPv4 or IPv6 packets addressed to the Routing Engine; the triggering packet characteristics are not public. The flaw is unauthenticated but does not affect Layer 2 filtering or Layer 3 filtering for connected hosts.

CVSS severity6.5
Medium
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper access control in Junos OS on EX/QFX switches allows remote attackers to bypass Routing Engine firewall filtering. The stateless IP firewall filter fails to evaluate certain IPv4 or IPv6 packets addressed to the Routing Engine; the triggering packet characteristics are not public. The flaw is unauthenticated but does not affect Layer 2 filtering or Layer 3 filtering for connected hosts.

The record

CVE
CVE-2020-1604
Published
Jan 15, 2020
Updated
Sep 16, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-284
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=14.1X53 <14.1X53-D12
  2. Affected versionversion=14.1X53 <14.1X53-D48
  3. Affected versionversion=14.1X53 <14.1X53-D52
  4. Affected versionversion=15.1 <15.1R7-S3
  5. Affected versionversion=16.1 <16.1R7
  6. Affected versionversion=17.1 <17.1R3
  7. Affected versionversion=17.2 <17.2R3
  8. Affected versionversion=17.3 <17.3R2-S5, 17.3R3
  9. Affected versionversion=17.4 <17.4R2
  10. Affected versionversion=18.1 <18.1R3
  11. Affected versionversion=18.2 <18.2R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=14.1X53 <14.1X53-D12; version=14.1X53 <14.1X53-D48; version=14.1X53 <14.1X53-D52; version=15.1 <15.1R7-S3; version=16.1 <16.1R7; version=17.1 <17.1R3; version=17.2 <17.2R3; version=17.3 <17.3R2-S5, 17.3R3; version=17.4 <17.4R2; version=18.1 <18.1R3; version=18.2 <18.2R2

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
6.5Juniper NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo