Junos OS: NFX350: Password hashes stored in world-readable format

The Juniper Device Manager (JDM) container, used by the disaggregated Junos OS architecture on Juniper Networks NFX350 Series devices, stores password hashes in the world-readable file /etc/passwd. This is not a security best current practice as it can allow an attacker with access to the local filesystem the ability to brute-force decrypt password hashes stored on the system. This issue affects Juniper Networks Junos OS on NFX350: 19.4 versions prior to 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2.