CVEvulnerability

CVE-2023-36851

5.3 MEDIUM Known exploited Published 2023-09-27 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Juniper Junos OS SRX Series Missing Authentication for Critical Function Vulnerability — Juniper Junos OS

Juniper Junos OS on SRX Series contains a missing authentication for critical function vulnerability that allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.php that doesn't require authentication, an attacker is able to upload arbitrary files via J-Web, leading to a loss of integrity for a certain part of the file system, 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-2023-36851

Status: Analyzed
Published: 2023-09-27
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-306

Description

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.php that doesn't require authentication, an attacker is able to upload and download arbitrary files via J-Web, leading to a loss of integrity or confidentiality, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on SRX Series: * 21.2 versions prior to 21.2R3-S8; * 21.4 versions prior to 21.4R3-S6; * 22.1 versions prior to 22.1R3-S5; * 22.2 versions prior to 22.2R3-S3; * 22.3 versions prior to 22.3R3-S2; * 22.4 versions prior to 22,4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S2, 23.2R2.

Affected configurations

• juniper junos 21.2 • 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-306 Missing Authentication for Critical Functionality weakness

References