title: Junos OS: A XSS vulnerability allows an attacker to execute commands on a target J-Web session
description: A Cross-site Scripting (XSS) vulnerability in Juniper Networks Junos OS J-Web allows an attacker to construct a URL that when visited by another user enables the attacker to execute commands with the target's permissions, including an administrator. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S10, 18.4R3-S9; 19.1 versions prior to 19.1R2-S3, 19.1R3-S6; 19.2 versions prior to 19.2R1-S8, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S2; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.
problem types: CWE-79 Cross-site Scripting (XSS)
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 12.3R12-S19, status: affected, version: 12.3, versionType: custom
lessThan: 15.1R7-S10, status: affected, version: 15.1, versionType: custom
lessThan: 18.3R3-S5, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R2-S10, 18.4R3-S9, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R2-S3, 19.1R3-S6, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R1-S8, 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-S5, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R3-S2, 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-S2, 20.4R3, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R1-S1, 21.1R2, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R1-S1, 21.2R2, status: affected, version: 21.2, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: REQUIRED
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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: 12.3R12-S19, 15.1R7-S10, 18.3R3-S5, 18.4R2-S10, 18.4R3-S9, 19.1R2-S3, 19.1R3-S6, 19.2R1-S8, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R3-S5, 20.1R3-S2, 20.2R3-S2, 20.3R3, 20.4R2-S2, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1-S1, 21.2R2, 21.3R1, and all subsequent releases.
workarounds: To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted administrative networks, hosts and users.
Alternatively, J-Web can be disabled.