CVE-2023-36847: Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability

Medium severity, CVSS 5.3. Actively exploited: in CISA KEV since 2023-11-13. EPSS: 83.5% chance of exploitation in the next 30 days.

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to installAppPackage.php that doesn't require authentication an attacker is able to upload arbitrary files via J-Web, leading to a loss of integrity for a certain part of the file system, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on EX Series: * All versions prior to 20.4R3-S8; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3.

Affected products

• Juniper Junos: before 20.4 (fixed in 20.4); version 20.4 only; version 21.1 only; version 21.2 only; version 21.3 only; version 21.4 only; …

Published 2023-08-17. Last modified 2026-06-17.