CVE-2023-36844: Juniper Junos OS EX Series PHP External Variable Modification Vulnerability

CISA Known Exploited Vulnerabilities

Name

Juniper Junos OS EX Series PHP External Variable Modification Vulnerability

Vendor

Juniper

Product

Junos OS

Added to the catalog

2023-11-13

Due date for US federal agencies

2023-11-17

Weaknesses

CWE-473

Catalog version

2026.10.30

Juniper Junos OS on EX Series contains a PHP external variable modification vulnerability that 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.

Required action (CISA)

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://supportportal.juniper.net/s/article/2023-08-Out-of-Cycle-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Multiple-vulnerabilities-in-J-Web-can-be-combined-to-allow-a-preAuth-Remote-Code-Execution?language=en_US
• https://nvd.nist.gov/vuln/detail/CVE-2023-36844

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2023-08-17T20:15:10.267

Last modified

2026-06-17T06:07:12.573

Weaknesses

CWE-473, NVD-CWE-Other

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.

References

• http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
• https://supportportal.juniper.net/JSA72300 (Vendor Advisory)
• http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.html (Exploit, Third Party Advisory, VDB Entry)
• https://supportportal.juniper.net/JSA72300 (Vendor Advisory)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36844 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:08.214Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2023-36844

CVE record

Title (CNA)

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

Assigner

juniper

State

PUBLISHED

Published

2023-08-17T19:17:47.904Z

Updated

2025-10-21T23:05:40.828Z

Problem types

CWE-473 PHP External Variable Modification

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.

References

• https://supportportal.juniper.net/JSA72300
• http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.html

Read on 2026-11-03T02:04:02.902Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2023/36xxx/CVE-2023-36844.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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