# CVE-2023-44191: Junos OS: QFX5000 Series and EX4000 Series: Denial of Service (DoS) on a large scale VLAN due to PFE hogging

> An unauthenticated attacker can cause a denial of service on Juniper QFX5000 and EX4000 switches by sending specific DHCP packets when many VLANs are configured.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 12 Oct 2023
- **Updated:** 19 Sep 2024
- **Also known as:** GHSA-gg84-68cr-5wgm

## What is CVE-2023-44191?

CVE-2023-44191 is a high-severity denial of service vulnerability in Juniper Junos, published on 12 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Allocation of Resources Without Limits or Throttling vulnerability in Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS).

On all Junos OS QFX5000 Series and EX4000 Series platforms, when a high number of VLANs are configured, a specific DHCP packet will cause PFE hogging which will lead to dropping of socket connections.

This issue affects:

Juniper Networks Junos OS on QFX5000 Series and EX4000 Series

  *  21.1 versions prior to 21.1R3-S5;
  *  21.2 versions prior to 21.2R3-S5;
  *  21.3 versions prior to 21.3R3-S5;
  *  21.4 versions prior to 21.4R3-S4;
  *  22.1 versions prior to 22.1R3-S3;
  *  22.2 versions prior to 22.2R3-S1;
  *  22.3 versions prior to 22.3R2-S2, 22.3R3;
  *  22.4 versions prior to 22.4R2.

This issue does not affect Juniper Networks Junos OS versions prior to 21.1R1

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2023-44191?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2023-44191?

No fix has been published for CVE-2023-44191 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-44191 being exploited?

There is no known exploitation of CVE-2023-44191 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-2023-44191 and fix it if it is affected.

What it is: CVE-2023-44191 is a high-severity denial of service vulnerability in Juniper Junos, published on 12 Oct 2023. 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-2023-44191 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-2023-44191/ (Markdown: https://insights.sbomify.com/CVE-2023-44191/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-44191
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-44191
- OSV: https://osv.dev/vulnerability/CVE-2023-44191

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-44191/
Summaries are generated and may contain mistakes; the official description above is the record.