---
title: "CVE-2023-36844: Junos OS: EX Series: A PHP vulnerability… | CubePath"
description: "A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker…"
language: en
source: https://cubepath.com/security/cve/CVE-2023-36844
---

# CVE-2023-36844: Junos OS: EX Series: A PHP vulnerability… | CubePath

## 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.

Official description from the CVE record, published by juniper. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2023-36844)

## Key data

### CVSS 3.1 Medium 5.3

Score published by juniper in the CVE record.

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

| Metric                 | Value     | What it means                                                                       |
| ---------------------- | --------- | ----------------------------------------------------------------------------------- |
| Attack vector          | Network   | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity      | Low       | No special conditions are needed. The attack can be repeated at will.               |
| Privileges required    | None      | No account or privileges are needed.                                                |
| User interaction       | None      | No action from any user is needed.                                                  |
| Scope                  | Unchanged | The impact stays within the vulnerable component.                                   |
| Confidentiality impact | None      | No effect on the secrecy of data.                                                   |
| Integrity impact       | Low       | Limited effect on the trustworthiness of data.                                      |
| Availability impact    | None      | No effect on availability.                                                          |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.89958 (90.0% probability)

Percentile

99.8%

Scores of

Nov 10, 2026

Model

v2026.06.15

### CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog

Juniper Junos OS EX Series PHP External Variable Modification Vulnerability

Added to the catalog

Nov 13, 2023

Federal due date

Nov 17, 2023

### CISA assessment as of Nov 15, 2023

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation

Recorded by CISA as active

Automatable

yes

Technical impact

total

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-473](https://cwe.mitre.org/data/definitions/473.html) PHP External Variable Modification

## Affected products

Products listed in the CVE record, as the CNA published them.

- Juniper Networks Junos OS

  - affected: before 20.4R3-S9
  - affected: 21.1 up to before 21.1\*
  - affected: 21.2 up to before 21.2R3-S6
  - affected: 21.3 up to before 21.3R3-S5
  - affected: 21.4 up to before 21.4R3-S5
  - affected: 22.1 up to before 22.1R3-S4
  - affected: 22.2 up to before 22.2R3-S2
  - affected: 22.3 up to before 22.3R3-S1
  - affected: 22.4 up to before 22.4R2-S2, 22.4R3
  - affected: 23.2 up to before 23.2R1-S1, 23.2R2

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [supportportal.juniper.net/JSA72300](https://supportportal.juniper.net/JSA72300) vendor-advisory mitigation
- [packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-E…](http://packetstormsecurity.com/files/174865/Juniper-SRX-Firewall-EX-Switch-Remote-Code-Execution.html)

## Timeline

1. ID reserved Jun 27, 2023
2. Record published Aug 17, 2023
3. Added to CISA KEV Nov 13, 2023
4. Record last updated Oct 21, 2025

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:24 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)