title: Junos OS: J-Web allows a locally authenticated attacker to escalate their privileges to root.
description: An Improper Input Validation vulnerability in J-Web of Juniper Networks Junos OS allows a locally authenticated attacker to escalate their privileges to root over the target device. junos:18.3R3-S5 junos:18.4R3-S9 junos:19.1R3-S6 junos:19.3R2-S6 junos:19.3R3-S3 junos:19.4R1-S4 junos:19.4R3-S4 junos:20.1R2-S2 junos:20.1R3 junos:20.2R3-S1 junos:20.3X75-D20 junos:20.3X75-D30 junos:20.4R2-S1 junos:20.4R3 junos:21.1R1-S1 junos:21.1R2 junos:21.2R1 junos:21.3R1 This issue affects: Juniper Networks Junos OS 19.3 versions 19.3R1 and above prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 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. This issue does not affect Juniper Networks Junos OS versions prior to 19.3R1.
problem types: CWE-20 Improper Input Validation
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 19.3R1, status: unaffected, version: unspecified, versionType: custom
changes: [at: 19.3R2-S6, 19.3R3-S3, status: unaffected], lessThan: 19.3*, status: affected, version: 19.3R1, versionType: custom
lessThan: 19.4R3-S5, 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
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/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.  However, a proof-of-concept exploit does exist in the wild.
solutions: The following software releases have been updated to resolve this specific issue: 19.3R2-S6, 19.3R3-S3, 19.4R3-S5, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3, 20.4R2-S1, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1, and all subsequent releases.
In addition to the above fixed releases, for the following not-affected releases additional security enhancements were included in Junos OS 18.3R3-S5, 18.4R3-S9, 19.1R3-S6 as a result of resolving this issue.
workarounds: There are no viable workarounds for this issue other than disabling J-Web.
To reduce the risk of exploitation of these issues, use access lists or firewall filters to limit access to only trusted administrative networks, hosts and users.