title: Junos OS and Junos OS Evolved: Local Privilege Escalation vulnerability
description: A local privilege escalation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privileged user to cause the Juniper DHCP daemon (jdhcpd) process to crash, resulting in a Denial of Service (DoS), or execute arbitrary commands as root. Continued processing of malicious input will repeatedly crash the system and sustain the Denial of Service (DoS) condition. Systems are only vulnerable if jdhcpd is running, which can be confirmed via the 'show system processes' command. For example: root@host# run show system processes extensive | match dhcp 26537 root -16 0 97568K 13692K RUN 0 0:01 3.71% jdhcpd This issue affects: Juniper Networks Junos OS: All versions, including the following supported releases: 15.1 versions prior to 15.1R7-S10; 17.4 versions prior to 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO; All versions of 21.1-EVO.
problem types: CWE-269 Improper Privilege Management
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 15.1R7-S10, status: affected, version: 15.1, versionType: custom
lessThan: 17.4R3-S5, status: affected, version: 17.4, versionType: custom
lessThan: 18.3R3-S5, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R3-S9, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R3-S6, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R1-S7, 19.2R3-S3, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R2-S6, 19.3R3-S3, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R3-S6, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R2-S2, 20.1R3-S1, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R3-S2, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R3, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R2-S1, 20.4R3, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R1-S1, 21.1R2, status: affected, version: 21.1, versionType: custom
}
{
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 20.4R2-S3-EVO, status: affected, version: unspecified, versionType: custom
lessThan: 21.1*, status: affected, version: 21.1R1-EVO, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 7.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/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 15.1R7-S10, 17.4R3-S5, 18.3R3-S5, 18.4R3-S9, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R3-S6, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3, 20.4R2-S1, 20.4R3, 21.1R1-S1, 21.1R2, 21.1R3, 21.2R1, and all subsequent releases.
Junos OS Evolved 20.4R2-S3-EVO, 21.2R1-EVO, and all subsequent releases.
workarounds: Use access lists or firewall filters to limit access to the device via CLI only from trusted hosts and from trusted administrators.