CVE-2021-31350

HIGH

Juniper Junos OS and Junos OS Evolved - Authenticated Privilege Escalation via JET API gRPC Framework

Title source: llm
STIX 2.1

Description

An Improper Privilege Management vulnerability in the gRPC framework, used by the Juniper Extension Toolkit (JET) API on Juniper Networks Junos OS and Junos OS Evolved, allows a network-based, low-privileged authenticated attacker to perform operations as root, leading to complete compromise of the targeted system. The issue is caused by the JET service daemon (jsd) process authenticating the user, then passing configuration operations directly to the management daemon (mgd) process, which runs as root. This issue affects Juniper Networks Junos OS: 18.4 versions prior to 18.4R1-S8, 18.4R2-S8, 18.4R3-S8; 19.1 versions prior to 19.1R2-S3, 19.1R3-S5; 19.2 versions prior to 19.2R1-S7, 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2. This issue does not affect Juniper Networks Junos OS versions prior to 18.4R1. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-EVO; 21.1-EVO versions prior to 21.1R2-EVO.

References (1)

Core 1
Core References
Patch, Vendor Advisory x_refsource_confirm
https://kb.juniper.net/JSA11215

Scores

CVSS v3 7.5
EPSS 0.0034
EPSS Percentile 57.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-269
Status published
Products (6)
juniper/junos 18.4 (11 CPE variants)
juniper/junos 19.1 (12 CPE variants)
juniper/junos 19.2 (9 CPE variants)
juniper/junos 19.3 (10 CPE variants)
juniper/junos 19.4 r1 (6 CPE variants)
juniper/junos 20.1 r1 (2 CPE variants)
Published Oct 19, 2021
Tracked Since Feb 18, 2026