CVE-2020-1628Network attack vector

Information disclosure via internal traffic egress

Published Apr 8, 2020 · Updated Sep 16, 2024

Information exposure in Juniper Networks Junos OS on EX4300 switches allows remote attackers to receive internal device traffic. The switch forwards packets sourced from the RE-to-PFE 128.0.0.0/2 internal network onto egress interfaces instead of keeping that control traffic inside the device. No authentication or user interaction is required; exposed packets reveal heartbeats, kernel versions, and configuration details, without reported integrity or availability impact.

CVSS severity5.3
Medium
EPSS probability1.29%
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

Information exposure in Juniper Networks Junos OS on EX4300 switches allows remote attackers to receive internal device traffic. The switch forwards packets sourced from the RE-to-PFE 128.0.0.0/2 internal network onto egress interfaces instead of keeping that control traffic inside the device. No authentication or user interaction is required; exposed packets reveal heartbeats, kernel versions, and configuration details, without reported integrity or availability impact.

The record

CVE
CVE-2020-1628
Published
Apr 8, 2020
Updated
Sep 16, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-200, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 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-D53
  2. Affected versionversion=15.1 <15.1R7-S6
  3. Affected versionversion=15.1X49 <15.1X49-D200, 15.1X49-D210
  4. Affected versionversion=16.1 <16.1R7-S7
  5. Affected versionversion=17.1 <17.1R2-S11, 17.1R3-S2
  6. Affected versionversion=17.2 <17.2R3-S3
  7. Affected versionversion=17.3 <17.3R2-S5, 17.3R3-S7
  8. Affected versionversion=17.4 <17.4R2-S9, 17.4R3
  9. Affected versionversion=18.1 <18.1R3-S8
  10. Affected versionversion=18.2 <18.2R3-S2
  11. Affected versionversion=18.3 <18.3R2-S3, 18.3R3, 18.3R3-S1
  12. Affected versionversion=18.4 <18.4R1-S5, 18.4R2-S3, 18.4R3
  13. Affected versionversion=19.1 <19.1R1-S4, 19.1R2
  14. Affected versionversion=19.2 <19.2R1-S4, 19.2R2
  15. Affected versionversion=19.3 <19.3R1-S1, 19.3R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=14.1X53 <14.1X53-D53; version=15.1 <15.1R7-S6; version=15.1X49 <15.1X49-D200, 15.1X49-D210; version=16.1 <16.1R7-S7; version=17.1 <17.1R2-S11, 17.1R3-S2; version=17.2 <17.2R3-S3; version=17.3 <17.3R2-S5, 17.3R3-S7; version=17.4 <17.4R2-S9, 17.4R3; version=18.1 <18.1R3-S8; version=18.2 <18.2R3-S2; version=18.3 <18.3R2-S3, 18.3R3, 18.3R3-S1; version=18.4 <18.4R1-S5, 18.4R2-S3, 18.4R3; version=19.1 <19.1R1-S4, 19.1R2; version=19.2 <19.2R1-S4, 19.2R2; version=19.3 <19.3R1-S1, 19.3R2

Published CVSS scores

5.3Juniper NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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-200Information Exposure
T1040Network Sniffing

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