Default credentials

Juniper Junos OS before 12.1X44-D50, 12.1X46 before 12.1X46-D35, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R9, 12.3X48 before 12.3X48-D15, 13.2 before 13.2R7, 13.2X51 before 13.2X51-D35, 13.3 before 13.3R6, 14.1 before 14.1R5, 14.1X50 before 14.1X50-D105, 14.1X51 before 14.1X51-D70, 14.1X53 before 14.1X53-D25, 14.1X55 before 14.1X55-D20, 14.2 before 14.2R1, 15.1 before 15.1F2 or 15.1R1, and 15.1X49 before 15.1X49-D10 does not require a password for the root user when pam.conf is “corrupted,” which allows local users to gain root privileges by modifying the file.