---
id: "CVE-2023-36846"
kind: "vulnerability"
aliases: ["CVE-2023-36846"]
title: "juniper junos: A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an\u2026"
severity: "high"
cvss: 5.3
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Juniper Junos OS", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": ["20.4"], "affected": "< 20.4", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 20.4", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 21.1", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 21.2", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 21.3", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 21.4", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 22.1", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 22.2", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 22.3", "ecosystem": "vendor"}, {"name": "juniper junos", "fixed": [], "affected": "= 22.4", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "j-web", "juniper", "junos", "srx"]
not_affected_if: ["j-web-disabled", "non-srx-platform"]
published_at: "2023-08-17T20:15:10+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T22:29:04+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-36846", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-36846", "first_seen_at": "2026-10-23T22:29:04+00:00"}]
---

# juniper junos: A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an…

Juniper Junos OS on SRX firewalls has a J-Web flaw where a request to user.php skips authentication and lets an attacker upload arbitrary files. The sources say this is exploited in the wild and can chain into further flaws.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Juniper Junos OS affected ? fixed ?
- vendor:juniper junos affected < 20.4 fixed 20.4
- vendor:juniper junos affected = 20.4 fixed ?
- vendor:juniper junos affected = 21.1 fixed ?
- vendor:juniper junos affected = 21.2 fixed ?
- vendor:juniper junos affected = 21.3 fixed ?
- vendor:juniper junos affected = 21.4 fixed ?
- vendor:juniper junos affected = 22.1 fixed ?
- vendor:juniper junos affected = 22.2 fixed ?
- vendor:juniper junos affected = 22.3 fixed ?
- vendor:juniper junos affected = 22.4 fixed ?

## Fix

Apply the Juniper mitigation for CVE-2023-36846 per vendor instructions, or stop using the affected product if no mitigation is available.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-36846
- 2026-10-23T22:29:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-36846

## From the sources

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 user.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.


This issue affects Juniper Networks Junos OS on SRX Series:



  *  All versions prior to 20.4R3-S8;
  *  21.1 versions 21.1R1 and later;
  *  21.2 versions prior to 21.2R3-S6;
  *  21.3 versions 

prior to 

 21.3R3-S5;
  *  21.4 versions 

prior to 

21.4R3-S5;
  *  22.1 versions 

prior to 

22.1R3-S3;
  *  22.2 versions 

prior to 

22.2R3-S2;
  *  22.3 versions 

prior to 

22.3R2-S2, 22.3R3;
  *  22.4 versions 

prior to 

22.4R2-S1, 22.4R3.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_