# CVE-2023-36851: Juniper Junos OS SRX Series Missing Authentication for Critical Function

> Unauthenticated attackers can upload and download arbitrary files on Juniper SRX devices via J-Web, compromising file integrity and confidentiality.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Yes, since 13 Nov 2023 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Sep 2023
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-792v-3cgw-26xq

## What is CVE-2023-36851?

CVE-2023-36851 is a medium-severity missing authorization vulnerability in Juniper Junos, published on 26 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2023-36851?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2023-36851?

No fix has been published for CVE-2023-36851 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 17 Nov 2023.

## Is CVE-2023-36851 being exploited?

Yes. Attackers have exploited CVE-2023-36851 in the wild since at least 13 Nov 2023.

## Other vulnerabilities in Juniper Junos

- [CVE-2023-36845](https://insights.sbomify.com/CVE-2023-36845/): Juniper Junos OS EX Series and SRX Series PHP External Variable Modification (critical 9.8, exploited in the wild)
- [CVE-2020-1631](https://insights.sbomify.com/CVE-2020-1631/): Juniper Junos OS Path Traversal (high 8.8, exploited in the wild)
- [CVE-2025-21590](https://insights.sbomify.com/CVE-2025-21590/): Juniper Junos OS Improper Isolation or Compartmentalization (medium 6.7, exploited in the wild)
- [CVE-2023-36844](https://insights.sbomify.com/CVE-2023-36844/): Juniper Junos OS EX Series PHP External Variable Modification (medium 5.3, exploited in the wild)
- [CVE-2023-36846](https://insights.sbomify.com/CVE-2023-36846/): Juniper Junos OS SRX Series Missing Authentication for Critical Function (medium 5.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-36851 and fix it if it is affected.

What it is: CVE-2023-36851 is a medium-severity missing authorization vulnerability in Juniper Junos, published on 26 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2023-36851 in the wild since at least 13 Nov 2023.

Affected product: Juniper Junos. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-36851/ (Markdown: https://insights.sbomify.com/CVE-2023-36851/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-36851
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-36851
- OSV: https://osv.dev/vulnerability/CVE-2023-36851

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-36851/
Summaries are generated and may contain mistakes; the official description above is the record.