# CVE-2016-4923: Junos J-Web: Cross Site Scripting Vulnerability

> Remote unauthenticated attackers can inject scripts into Junos J-Web to steal credentials and perform administrative actions on the device.

- **Severity:** High 8.0 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Oct 2017
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-8p6g-483j-rff7

## What is CVE-2016-4923?

CVE-2016-4923 is a high-severity cross-site scripting vulnerability in Juniper Junos, published on 13 Oct 2017. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Insufficient cross site scripting protection in J-Web component in Juniper Networks Junos OS may potentially allow a remote unauthenticated user to inject web script or HTML and steal sensitive data and credentials from a J-Web session and to perform administrative actions on the Junos device. Juniper SIRT is not aware of any malicious exploitation of this vulnerability. Affected releases are Juniper Networks Junos OS 11.4 prior to 11.4R13-S3; 12.1X44 prior to 12.1X44-D60; 12.1X46 prior to 12.1X46-D40; 12.1X47 prior to 12.1X47-D30; 12.3 prior to 12.3R11; 12.3X48 prior to 12.3X48-D20; 13.2X51 prior to 13.2X51-D39, 13.2X51-D40; 13.3 prior to 13.3R9; 14.1 prior to 14.1R6; 14.2 prior to 14.2R6; 15.1 prior to 15.1R3; 15.1X49 prior to 15.1X49-D20; 15.1X53 prior to 15.1X53-D57.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2016-4923?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2016-4923?

No fix has been published for CVE-2016-4923 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-4923 being exploited?

There is no known exploitation of CVE-2016-4923 in the wild and no public exploit code.

## 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-2023-36851](https://insights.sbomify.com/CVE-2023-36851/): Juniper Junos OS SRX Series Missing Authentication for Critical Function (medium 5.3, 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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-4923 and fix it if it is affected.

What it is: CVE-2016-4923 is a high-severity cross-site scripting vulnerability in Juniper Junos, published on 13 Oct 2017. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2016-4923 in the wild and no public exploit code.

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-2016-4923/ (Markdown: https://insights.sbomify.com/CVE-2016-4923/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-4923
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-4923
- OSV: https://osv.dev/vulnerability/CVE-2016-4923

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-4923/
Summaries are generated and may contain mistakes; the official description above is the record.