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Vulnerability record · CVE-2021-31384 · published 19 October 2021

CVE-2021-31384: Juniper junos improper authorization vulnerability

Juniper · Junos

Due to a Missing Authorization weakness and Insufficient Granularity of Access Control in a specific device configuration, a vulnerability exists in Juniper Networks Junos OS on SRX Series whereby an attacker who attempts to access J-Web administrative interfaces can successfully do so from any device interface regardless of the web-management configuration and filter rules which may otherwise protect access to J-Web. This issue affects: Juniper Networks Junos OS SRX Series 20.4 version 20.4R1 and later 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 20.4R1.

10.0 CVSS 3.1 Critical EPSS 1.2% · top 34.1% CWE-285 · Improper authorizationCWE-551 · CWE-551
10.0CVSS 3.1 base score, v2 7.5
1.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References
17 Jun 2026Last modified by NVD

Description

Due to a Missing Authorization weakness and Insufficient Granularity of Access Control in a specific device configuration, a vulnerability exists in Juniper Networks Junos OS on SRX Series whereby an attacker who attempts to access J-Web administrative interfaces can successfully do so from any device interface regardless of the web-management configuration and filter rules which may otherwise protect access to J-Web. This issue affects: Juniper Networks Junos OS SRX Series 20.4 version 20.4R1 and later 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 20.4R1.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://kb.juniper.net/ Permissions Required
https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11252 Vendor Advisory
https://kb.juniper.net/ Permissions Required

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-36845Juniper Junos OS J-Web PHP variable modification RCEJ-Web in Junos OS on EX Series and SRX Series mishandles the PHP PHPRC environment variable, letting a crafted request alter the PHP execution enviro…KEVEPSS 95%analysed9.8CVE-2020-1631Juniper Junos OS J-Web HTTP service path traversal and local file inclusionThe HTTP/HTTPS service behind J-Web, Web Authentication, Dynamic-VPN, Firewall Authentication Pass-Through with Web-Redirect, and ZTP in Junos OS doe…KEVEPSS 4.8%analysed6.7CVE-2025-21590Juniper Junos OS kernel improper isolation allows local code injectionJunos OS contains an improper isolation or compartmentalization flaw in the kernel that lets a local attacker with shell access inject arbitrary code…KEVEPSS 1.7%analysed5.3CVE-2023-36851Juniper Junos OS SRX J-Web missing authentication allows file upload/downloadJunos OS on SRX Series exposes webauth_operation.php without authentication, letting a network attacker upload and download arbitrary files through J…KEVEPSS 1.1%analysed5.3CVE-2023-36844Juniper Junos OS EX Series J-Web PHP Environment Variable ModificationJ-Web on Junos OS for EX Series fails to properly restrict external PHP variable modification, letting an unauthenticated network attacker alter impo…KEVEPSS 90%analysed5.3CVE-2023-36846Juniper Junos OS SRX J-Web Missing Authentication Allows File UploadJunos OS on SRX Series fails to require authentication for a critical function in user.php reachable through J-Web, letting an unauthenticated networ…KEVEPSS 93%analysed5.3CVE-2023-36847Juniper Junos OS EX Series J-Web installAppPackage.php missing authenticationJunos OS on EX Series exposes installAppPackage.php through J-Web without requiring authentication. An unauthenticated network attacker can upload ar…KEVEPSS 83%analysed10.0CVE-2021-0248Juniper junos hard-coded credentials vulnerabilityThis issue is not applicable to NFX NextGen Software. On NFX Series devices the use of Hard-coded Credentials in Juniper Networks Junos OS allows an …EPSS 1.0%

Source: NIST National Vulnerability Database (record CVE-2021-31384), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.