CVE-2020-1666

Name: CVE-2020-1666
Creator: NVD / NIST
Published: 2020-10-16T21:15:12.677+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.6/10EPSS 0.32%

Last modified Jun 17, 2026

CVE-2020-1666 is a medium-severity vulnerability rated 6.6/10 on the CVSS scale. The system console configuration option 'log-out-on-disconnect' In Juniper Networks Junos OS Evolved fails to log out an active CLI session when the console cable is disconnected. This could allow a malicious attacker with physical access to the console the ability to resume a previous interactive session and possibly gain administrative privileges. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

Description

The system console configuration option 'log-out-on-disconnect' In Juniper Networks Junos OS Evolved fails to log out an active CLI session when the console cable is disconnected. This could allow a malicious attacker with physical access to the console the ability to resume a previous interactive session and possibly gain administrative privileges. This issue affects all Juniper Networks Junos OS Evolved versions after 18.4R1-EVO, prior to 20.2R1-EVO.

Metrics

CVSS 3.1

6.6/10

CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.32%

24.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos Os Evolved	19.2	R1
Juniper	Junos Os Evolved	19.3	R2
Juniper	Junos Os Evolved	19.4	R1
Juniper	Junos Os Evolved	20.1	R1

References

https://kb.juniper.net/JSA11063Vendor Advisory
https://kb.juniper.net/JSA11063Vendor Advisory

Timeline

Published: Oct 16, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-1666?

How severe is CVE-2020-1666?

CVE-2020-1666 has a CVSS score of 6.6/10 (MEDIUM severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.

How do I fix CVE-2020-1666?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-1666?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST