title: Junos OS: J-Web can be compromised through reflected XSS attacks
description: A reflected Cross-site Scripting (XSS) vulnerability in J-Web of Juniper Networks Junos OS allows a network-based authenticated attacker to run malicious scripts reflected off J-Web to the victim's browser in the context of their session within J-Web. This may allow the attacker to gain control of the device or attack other authenticated user sessions. This issue affects: Juniper Networks Junos OS All 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 19.2R3-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-S4; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2.
problem types: CWE-79 Cross-site Scripting (XSS)
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 18.3R3-S5, status: affected, version: unspecified, 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: 19.2R3-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-S4, 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: 20.4R3, 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
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: REQUIRED
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/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: 18.3R3-S5, 18.4R3-S9, 19.1R3-S6, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R3-S5, 20.1R3-S4, 20.2R3-S2, 20.3R3, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1, 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.