title: Junos OS: J-Web can be compromised through reflected client-side HTTP parameter pollution attacks.
description: The improper handling of client-side parameters in J-Web of Juniper Networks Junos OS allows an attacker to perform a number of different malicious actions against a target device when a user is authenticated to J-Web. An attacker may be able to supersede existing parameters, including hardcoded parameters within the HTTP/S session, access and exploit variables, bypass web application firewall rules or input validation mechanisms, and otherwise alter and modify J-Web's normal behavior. An attacker may be able to transition victims to malicious web services, or exfiltrate sensitive information from otherwise secure web forms. This issue affects: Juniper Networks Junos OS: All versions prior to 17.4R3-S3; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R3-S6; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2.
problem types: CWE-233: Improper Handling of Parameters
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.4R3-S3, status: affected, version: unspecified, versionType: custom
lessThan: 18.1R3-S12, status: affected, version: 18.1, versionType: custom
lessThan: 18.2R3-S6, status: affected, version: 18.2, versionType: custom
lessThan: 18.3R3-S4, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R3-S6, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R3-S4, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R3-S1, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R3-S1, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R2-S2, 19.4R3, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R2, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R2, status: affected, version: 20.2, 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: 17.4R3-S3, 18.1R3-S12, 18.2R3-S6, 18.3R3-S4, 18.4R3-S6, 19.1R3-S4, 19.2R3-S1, 19.3R3-S1, 19.4R2-S2, 19.4R3, 20.1R2, 20.2R2, 20.3R1, and all subsequent releases.
workarounds: To reduce the risk of exploitation utilize common security BCPs to limit the exploitable surface by limiting access to network and device to trusted systems, administrators, networks and hosts.
Access the J-Web service from trusted hosts which may not be compromised by cross-site scripting attacks, for example, deploying jump hosts with no internet access.
Alternatively, disable J-Web.