CVE-2021-0252: Juniper Junos

High severity, CVSS 7.8. EPSS: 0.5% chance of exploitation in the next 30 days.

NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allowing an attacker to elevate their privileges via the Junos Device Management Daemon (JDMD) process. This issue affects Juniper Networks Junos OS on NFX Series: 18.1 version 18.1R1 and later versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S5, 19.2R2. This issue does not affect: Juniper Networks Junos OS versions prior to 18.1R1. This issue does not affect the JDMD as used by Junos Node Slicing such as External Servers use in conjunction with Junos Node Slicing and In-Chassis Junos Node Slicing on MX480, MX960, MX2008, MX2010, MX2020.

Affected products

• Juniper Junos: version 18.1 only; version 18.2 only; version 18.3 only; version 18.4 only; version 19.1 only; version 19.2 only

Published 2021-04-22. Last modified 2026-06-17.