# CVE-2019-0005: Security feature bypass in n/a

> Attackers can bypass IPv6 firewall filters on Juniper EX and QFX switches by using extension headers, allowing blocked packets to be forwarded.

- **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:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jan 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-8r5w-fx9q-rh85

## What is CVE-2019-0005?

CVE-2019-0005 is a medium-severity vulnerability in Juniper Junos, published on 15 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

On EX2300, EX3400, EX4600, QFX3K and QFX5K series, firewall filter configuration cannot perform packet matching on any IPv6 extension headers. This issue may allow IPv6 packets that should have been blocked to be forwarded. IPv4 packet filtering is unaffected by this vulnerability. Affected releases are Juniper Networks Junos OS on EX and QFX series;: 14.1X53 versions prior to 14.1X53-D47; 15.1 versions prior to 15.1R7; 15.1X53 versions prior to 15.1X53-D234 on QFX5200/QFX5110 series; 15.1X53 versions prior to 15.1X53-D591 on EX2300/EX3400 series; 16.1 versions prior to 16.1R7; 17.1 versions prior to 17.1R2-S10, 17.1R3; 17.2 versions prior to 17.2R3; 17.3 versions prior to 17.3R3; 17.4 versions prior to 17.4R2; 18.1 versions prior to 18.1R2.

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

## Which versions are affected by CVE-2019-0005?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2019-0005?

No fix has been published for CVE-2019-0005 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-0005 being exploited?

There is no known exploitation of CVE-2019-0005 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-2019-0005 and fix it if it is affected.

What it is: CVE-2019-0005 is a medium-severity vulnerability in Juniper Junos, published on 15 Jan 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-2019-0005 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-2019-0005/ (Markdown: https://insights.sbomify.com/CVE-2019-0005/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-0005
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-0005
- OSV: https://osv.dev/vulnerability/CVE-2019-0005

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-0005/
Summaries are generated and may contain mistakes; the official description above is the record.