# CVE-2019-0033: SRX Series: A remote attacker may cause a high CPU Denial of Service to the device when proxy ARP is configured.

> Remote attackers can cause high CPU denial of service on Juniper SRX devices when proxy ARP is enabled.

- **Severity:** High 7.5 (`CVSS:3.0/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:** 10 Apr 2019
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-cfxp-vw2r-fmfh

## What is CVE-2019-0033?

CVE-2019-0033 is a high-severity denial of service vulnerability in Juniper Junos, published on 10 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A firewall bypass vulnerability in the proxy ARP service of Juniper Networks Junos OS allows an attacker to cause a high CPU condition leading to a Denial of Service (DoS). This issue affects only IPv4. Affected releases are Juniper Networks Junos OS: 12.1X46 versions above and including 12.1X46-D25 prior to 12.1X46-D71, 12.1X46-D73 on SRX Series; 12.3X48 versions prior to 12.3X48-D50 on SRX Series; 15.1X49 versions prior to 15.1X49-D75 on SRX Series.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2019-0033?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2019-0033?

No fix has been published for CVE-2019-0033 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-0033 being exploited?

There is no known exploitation of CVE-2019-0033 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-2019-0033 and fix it if it is affected.

What it is: CVE-2019-0033 is a high-severity denial of service vulnerability in Juniper Junos, published on 10 Apr 2019. 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-2019-0033 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-2019-0033/ (Markdown: https://insights.sbomify.com/CVE-2019-0033/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-0033
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-0033
- OSV: https://osv.dev/vulnerability/CVE-2019-0033

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-0033/
Summaries are generated and may contain mistakes; the official description above is the record.