# CVE-2021-0248: NFX Series: Hard-coded credentials allow an attacker to take control of any instance through administrative interfaces.

> Hard-coded credentials in Juniper NFX Series devices allow attackers to take control via administrative interfaces.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-466r-grw5-cc98

## What is CVE-2021-0248?

CVE-2021-0248 is a critical vulnerability in Juniper Junos, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This issue is not applicable to NFX NextGen Software. On NFX Series devices the use of Hard-coded Credentials in Juniper Networks Junos OS allows an attacker to take over any instance of an NFX deployment. This issue is only exploitable through administrative interfaces. This issue affects: Juniper Networks Junos OS versions prior to 19.1R1 on NFX Series. No other platforms besides NFX Series devices are affected.

Weakness: CWE-798 (Use of Hard-coded Credentials)

## Which versions are affected by CVE-2021-0248?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2021-0248?

No fix has been published for CVE-2021-0248 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-0248 being exploited?

There is no known exploitation of CVE-2021-0248 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-2021-0248 and fix it if it is affected.

What it is: CVE-2021-0248 is a critical vulnerability in Juniper Junos, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-0248 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-2021-0248/ (Markdown: https://insights.sbomify.com/CVE-2021-0248/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0248
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0248
- OSV: https://osv.dev/vulnerability/CVE-2021-0248

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-0248/
Summaries are generated and may contain mistakes; the official description above is the record.