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2020-10 Security Bulletin: Junos OS Evolved: 'console log-out-on-disconnect' fails to terminate session on console cable disconnection (CVE-2020-1666)



Article ID: JSA11063 SECURITY_ADVISORIES Last Updated: 29 Oct 2020Version: 3.0
Product Affected:
This issue affects all versions of Junos OS Evolved after 18.4R1-EVO.

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.

Console log out on disconnect is enabled via the following configuration stanza:

[system ports console log-out-on-disconnect]

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was found during internal product security testing or research.

This issue has been assigned CVE-2020-1666.


The following software releases have been updated to resolve this specific issue: Junos OS Evolved 20.2R1-EVO and all subsequent releases.

This issue is being tracked as 1406238.

Limit access to the physical console to only trusted system administrators.
Software releases or updates are available for download at
Modification History:
2020-10-14: Initial Publication

CVSS Score:
6.6 (CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

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