CVE-2023-36844: Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variables | Kitploit

CVE-2023-36844

MediumPublished

Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variables

Published: Aug 17, 2023
Updated: Oct 21, 2025
Assigning CNA: juniper
Evidence observed: Nov 13, 2023

Primary CVSS

5.3/ 10Medium

nvd · CVSS 3.1

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

EPSS probability estimate

90.0%

High · next 30 days

Percentile: 99.8%
Model date: Sep 21, 2026

EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.

CISA Known Exploited

This CVE appears in the CISA Known Exploited Vulnerabilities catalog.

Summary

A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to control certain, important environment variables. Using a crafted request an attacker is able to modify certain PHP environment variables leading to partial loss of integrity, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on EX Series: * All versions prior to 20.4R3-S9; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S7; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S5; * 22.1 versions prior to 22.1R3-S4; * 22.2 versions prior to 22.2R3-S2; * 22.3 versions prior to 22.3R3-S1; * 22.4 versions prior to 22.4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S1, 23.2R2.

Sources

CVE-2023-36844_Juniper_RCEPoC
A Proof of Concept for chaining the CVEs [CVE-2023-36844, CVE-2023-36845, CVE-2023-36846, CVE-2023-36847] to achieve Remote Code Execution (phpinfo) in Juniper JunOS within SRX and EX Series products.Modified from original exploit developed by @watchTowr .
juniper-rce_cve-2023-36844Exploit
Proof-of-concept exploit chaining four CVEs (CVE-2023-36844-47) for pre-authentication remote code execution on Juniper JunOS SRX and EX series firewalls via PHP file upload and configuration injection.

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