CVE-2023-36844

MEDIUM KEV RANSOMWARE NUCLEI

Juniper Networks Junos OS on EX Series <20.4R3-S9 - PHP External Variable Modification

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2023-36844 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added November 13, 2023, with confirmed use in ransomware campaigns. EIP tracks 5 public exploits from researchers including watchtowrlabs, r3dcl1ff, dyeat. A Nuclei detection template is also available.

AI-analyzed exploit summary This PoC exploits a chain of vulnerabilities (CVE-2023-36844, CVE-2023-36845, CVE-2023-36846, CVE-2023-36847) in Juniper JunOS to achieve pre-authentication remote code execution. It uploads a malicious PHP file and a configuration file to trigger arbitrary code execution via environment variable manipulation.

Description

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.

Exploits (5)

nomisec WORKING POC 114 stars
by watchtowrlabs · remote
https://github.com/watchtowrlabs/juniper-rce_cve-2023-36844

This PoC exploits a chain of vulnerabilities (CVE-2023-36844, CVE-2023-36845, CVE-2023-36846, CVE-2023-36847) in Juniper JunOS to achieve pre-authentication remote code execution. It uploads a malicious PHP file and a configuration file to trigger arbitrary code execution via environment variable manipulation.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Juniper JunOS (SRX and EX Series)
No auth needed
Prerequisites: Network access to the target J-Web interface · Vulnerable version of Juniper JunOS
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC 5 stars
by r3dcl1ff · remote
https://github.com/r3dcl1ff/CVE-2023-36844_Juniper_RCE

This PoC exploits a chain of Juniper JunOS vulnerabilities (CVE-2023-36844, CVE-2023-36845, CVE-2023-36846, CVE-2023-36847) to achieve remote code execution by uploading a malicious PHP file and an INI file, then executing arbitrary PHP functions via the webauth_operation.php endpoint.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Juniper JunOS (SRX and EX Series)
No auth needed
Prerequisites: Network access to the target Juniper device · Vulnerable version of JunOS with exposed webauth_operation.php
devstral-2 · analyzed Feb 16, 2026 Full analysis →
github WORKING POC
by dyeat · pythonpoc
https://github.com/dyeat/cve-reproduction/tree/main/Juniper/Junos-OS/CVE-2023-36844

This repository contains a functional exploit for CVE-2023-36844, which leverages a PHP environment variable injection vulnerability in Juniper Junos OS J-Web to achieve pre-authentication remote code execution. The exploit uploads a malicious PHP file and an INI file to trigger arbitrary command execution.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Juniper Junos OS J-Web
No auth needed
Prerequisites: Target must be running vulnerable Juniper Junos OS J-Web · Network access to the target
devstral-2 · analyzed May 22, 2026 Full analysis →
nomisec WORKING POC
by Ap0dexMe0 · poc
https://github.com/Ap0dexMe0/CVE-2023-36844

This repository contains a functional exploit for CVE-2023-36844, a remote code execution vulnerability in Juniper JunOS within SRX and EX Series products. The exploit uploads a malicious PHP file and an INI file to trigger arbitrary code execution via a crafted request to the webauth_operation.php endpoint.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Juniper JunOS (SRX and EX Series)
No auth needed
Prerequisites: Access to the target's web interface · PHP file upload capability via webauth_operation.php
devstral-2 · analyzed May 16, 2026 Full analysis →
nomisec WORKING POC
by ThatNotEasy · remote
https://github.com/ThatNotEasy/CVE-2023-36844

This is a functional exploit for CVE-2023-36844, targeting Juniper JunOS in SRX and EX Series products. It achieves remote code execution by uploading a malicious PHP file and an INI file to manipulate PHP configuration, then executing arbitrary PHP functions.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Juniper JunOS (SRX and EX Series)
No auth needed
Prerequisites: Network access to the target device · PHP web interface exposed
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Nuclei Templates (1)

Juniper Devices - Remote Code Execution
MEDIUMVERIFIEDby princechaddha,ritikchaddha
Shodan: title:"Juniper Web Device Manager"

Scores

CVSS v3 5.3
EPSS 0.9422
EPSS Percentile 99.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation active
Automatable yes
Technical Impact total

Details

CISA KEV 2023-11-13
VulnCheck KEV 2023-08-29
InTheWild.io 2023-11-08
ENISA EUVD EUVD-2023-40764
Ransomware Use Confirmed
CWE
CWE-473
Status published
Products (4)
juniper/junos 20.4 (15 CPE variants)
juniper/junos 21.1 r1 (11 CPE variants)
juniper/junos 21.2 (14 CPE variants)
juniper/junos 21.3 (10 CPE variants)
Published Aug 17, 2023
KEV Added Nov 13, 2023
Tracked Since Feb 18, 2026