A missing authentication flaw in Junos OS command processing allows a privileged local user to execute commands as root on Linux-based line cards. The vulnerability can be exploited to gain unrestricted control over the affected hardware, enabling configuration changes, traffic manipulation and intrusion into the broader network.

All Junos OS releases before the referenced updates are vulnerable. Devices using Linux-based line cards such as MPC7, MPC8, MPC9, MPC10, MPC11, LC2101, LC2103, LC480, LC4800, LC9600, MX304 (built-in FPC), MX-SPC3, SRX5K-SPC3, EX9200-40XS, FPC3-PTX-U2, FPC3-PTX-U3, FPC3-SFF-PTX, LC1101, LC1102, LC1104, LC1105 are affected.

The vulnerability carries a CVSS score of 8.4, indicating high severity, and is not listed in the KEV catalog. Exploitation requires local privileged access to the device, which an attacker with such access can use to elevate to root on the line card. Once root privileges are obtained, the attacker can bypass security controls, tamper with routing, or carry out further attacks within the network.