Junos OS: An unauthenticated attacker with local access to the device can create a backdoor with root privileges

An Incorrect Default Permissions vulnerability in Juniper Networks Junos OS allows an unauthenticated attacker with local access to the device to create a backdoor with root privileges. The issue is caused by improper directory permissions on a certain system directory, allowing an attacker with access to this directory to create a backdoor with root privileges.

This issue affects Juniper Networks Junos OS:

• All versions prior to 20.4R3-S5;
• 21.1 versions prior to 21.1R3-S4;
• 21.2 versions prior to 21.2R3-S4;
• 21.3 versions prior to 21.3R3-S3;
• 21.4 versions prior to 21.4R3-S1.