Junos OS: EX and QFX Series: Console port authentication bypass vulnerability

published 2020-04-08 6y ago modified 2026-06-17 4mo ago also EUVD-2020-12486

cvss: 6.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

On Juniper Networks EX and QFX Series, an authentication bypass vulnerability may allow a user connected to the console port to login as root without any password. This issue might only occur in certain scenarios: • At the first reboot after performing device factory reset using the command “request system zeroize”; or • A temporary moment during the first reboot after the software upgrade when the device configured in Virtual Chassis mode. This issue affects Juniper Networks Junos OS on EX and QFX Series: 14.1X53 versions prior to 14.1X53-D53; 15.1 versions prior to 15.1R7-S4; 15.1X53 versions prior to 15.1X53-D593; 16.1 versions prior to 16.1R7-S4; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R3-S3; 17.3 versions prior to 17.3R2-S5, 17.3R3-S6; 17.4 versions prior to 17.4R2-S9, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R2; 18.3 versions prior to 18.3R1-S7, 18.3R2. This issue does not affect Juniper Networks Junos OS 12.3.

Patch / fix

fixed in 1

Juniper Networks Junos OS 12.3, 14.1X53-D53, 15.1R7-S4, 15.1X53-D593, 16.1R7-S4, 17.1R2-S11, 17.1R3-S1, 17.2R3-S3, 17.3R2-S5, 17.3R3-S6, 17.4R2-S9, 17.4R3, 18.1R3-S8, 18.2R2, 18.3R1-S7, 18.3R2

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Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.3	CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	6.8	CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.9	AV:L/AC:M/Au:N/C:C/I:C/A:C

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-288 Authentication Bypass Using an Alternate Path or Channel
CWE-287 Improper Authentication

References

kb.juniper.net /JSA11001
vendor-advisory

Sources

CVE List CVE-2020-1618
NVD CVE-2020-1618

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