CVE-2020-1666
Junos OS Evolved: 'console log-out-on-disconnect' fails to terminate session on console cable disconnection
- Published
- Updated
- Reserved
- Assigned by
- juniper
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.
Timeline
ID reserved
By juniper
- 12 months later
· 12 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| juniperCNA (assigner) | 3.1 | Medium6.6 | CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium6.6 | CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.6.
Weakness
Affected products
Juniper Networks · Junos OS Evolved
- affected unspecified – < 20.2R1-EVO
- unaffected unspecified – < 18.4R1-EVO
What to do
Solution: The following software releases have been updated to resolve this specific issue: Junos OS Evolved 20.2R1-EVO and all subsequent releases.
Workaround: Limit access to the physical console to only trusted system administrators.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References (1)
- https://kb.juniper.net/JSA11063 (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2020-1666)Record last updated .