Juniper Junos OS: commit script may allow unauthenticated root login upon reboot (JSA10835) (CVE-2018-0008)

Description

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.