Auth bypass in Juniper Ex2200

CVE-2018-0008

An unauthenticated root login may allow upon reboot when a commit script is used. A commit script allows a device administrator to execute certain instructions during commit, which is configured under the [system scripts commit] stanza. Certain commit scripts that work without a problem during normal commit may cause unexpected behavior upon reboot which can leave the system in a state where root CLI login is allowed without a password due to the system reverting to a "safe mode" authentication state. Lastly, only logging in physically to the console port as root, with no password, will work. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D71 on SRX; 12.3X48 versions prior to 12.3X48-D55 on SRX; 14.1 versions prior to 14.1R9; 14.1X53 versions prior to 14.1X53-D40 on QFX, EX; 14.2 versions prior to 14.2R7-S9, 14.2R8; 15.1 versions prior to 15.1F5-S7, 15.1F6-S8, 15.1R5-S6, 15.1R6; 15.1X49 versions prior to 15.1X49-D110 on SRX; 15.1X53 versions prior to 15.1X53-D232 on QFX5200/5110; 15.1X53 versions prior to 15.1X53-D49, 15.1X53-D470 on NFX; 15.1X53 versions prior to 15.1X53-D65 on QFX10K; 16.1 versions prior to 16.1R2. No other Juniper Networks products or platforms are affected by this issue.

Vulnerability class: Broken Authentication

EPSS: 0.005 (37.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.2 (Medium). Vector: CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-0008?
CVE-2018-0008 is a medium-severity vulnerability in Juniper Ex2200, classified under Improper Authentication. CVSS score: 6.2/10. Published 2018-01-10.
How severe is CVE-2018-0008?
Medium severity. CVSS v3 base score is 6.2 out of 10.
Is CVE-2018-0008 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.