CVEvulnerability

CVE-2023-36844

5.3 MEDIUM Known exploited Published 2023-08-17 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Juniper Junos OS EX Series PHP External Variable Modification Vulnerability — Juniper Junos OS

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.

Added to KEV: 2023-11-13
Remediation due: 2023-11-17
Ransomware use: Unknown
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
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

Status: Analyzed
Published: 2023-08-17
Last modified: 2026-06-17
Assigner: [email protected]
CVSS 3.1 ([email protected]): 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS 3.1 ([email protected]): 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weaknesses: CWE-473

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.

Affected configurations

• juniper junos (< 20.4) • juniper junos 20.4 • juniper junos 21.1 • juniper junos 21.2 • juniper junos 21.3 • juniper junos 21.4 • juniper junos 22.1 • juniper junos 22.2 • juniper junos 22.3 • juniper junos 22.4 • juniper junos 23.2

Weakness · CWE (1)

CWE-473 PHP External Variable Modification weakness

References