HIGH Juniper Networks, Inc. Vulnerability Alert

Product:

Junos OS

Summary

An Origin Validation Error vulnerability in an insufficiently protected file of Juniper Networks Junos OS on EX4600 Series and QFX5000 Series allows an unauthenticated attacker with physical access to the device to create a backdoor for complete control of the system. If a device is not configured with a root password, an attacker can modify a specific file, adding configurations that are not visible to the operator. This exploit is persistent across reboots and zeroization.

Details

Severity	Base Score	CVE
HIGH	7	CVE-2025-59957

Exploitation

To exploit this vulnerability, an attacker with physical access to the device can modify the /etc/config/-defaults[-flex].conf file. This modification allows the attacker to add unauthorized configurations, including users and IP addresses, which can lead to unauthorized access. The changes made are not visible to the actual operator, making detection difficult.

Affected Products

EX4600 Series: All versions before 21.4R3
QFX5000 Series: 22.2 versions before 22.2R3-S3

Mitigation

To mitigate this issue, it is essential to ensure that devices are configured with a root password. If a compromise is suspected, the device should be restored to a trusted initial configuration by reinstalling from physical media. For further assistance, contact Juniper Technical Assistance Center (JTAC).