title: Junos OS and Junos OS Evolved: Privilege escalation vulnerability in Juniper Extension Toolkit (JET)
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.
problem types: CWE-269 Improper Privilege Management
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 18.4R1, status: unaffected, version: unspecified, versionType: custom
lessThan: 18.4R1-S8, 18.4R2-S8, 18.4R3-S8, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R2-S3, 19.1R3-S5, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R1-S7, 19.2R3-S2, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R2-S6, 19.3R3-S2, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R1-S4, 19.4R2-S4, 19.4R3-S3, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R2-S2, 20.1R3, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R2-S3, 20.2R3, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R2-S1, 20.3R3, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R2, status: affected, version: 20.4, versionType: custom
}
{
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 20.4R2-EVO, status: affected, version: unspecified, versionType: custom
lessThan: 21.1R2-EVO, status: affected, version: 21.1-EVO, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
version: 3.1
]
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue:
Junos OS 18.4R1-S8, 18.4R2-S8, 18.4R3-S8, 19.1R2-S3, 19.1R3-S5, 19.2R1-S7, 19.2R3-S2, 19.3R2-S6, 19.3R3-S2, 19.4R1-S4, 19.4R2-S4, 19.4R3-S3, 20.1R2-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2-S1, 20.3R3, 20.4R2, 21.1R1, and all subsequent releases.
Junos OS Evolved 20.4R2-EVO, 21.1R2-EVO, 21.2R1-EVO, and all subsequent releases.
workarounds: Use access lists or firewall filters to limit access to the device via gRPC only from trusted hosts and from trusted administrators