# CVE-2020-1604: Junos OS: EX4300/EX4600/QFX3500/QFX5100 Series: Stateless IP firewall filter may fail to evaluate certain packets

> Attackers can bypass IP firewall filters on specific Juniper switches, allowing unauthorized packets to reach the Routing Engine.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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 2020
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-p4x7-xx93-8jx9

## What is CVE-2020-1604?

CVE-2020-1604 is a medium-severity vulnerability in Juniper Junos, published on 15 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

On EX4300, EX4600, QFX3500, and QFX5100 Series, a vulnerability in the IP firewall filter component may cause the firewall filter evaluation of certain packets to fail. This issue only affects firewall filter evaluation of certain packets destined to the device Routing Engine (RE). This issue does not affect the Layer 2 firewall filter evaluation nor does it affect the Layer 3 firewall filter evaluation destined to connected hosts. This issue may occur when evaluating both IPv4 or IPv6 packets. This issue affects Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D12 on QFX5100 Series and EX4600 Series; 14.1X53 versions prior to 14.1X53-D52 on QFX3500 Series; 14.1X53 versions prior to 14.1X53-D48 on EX4300 Series; 15.1 versions prior to 15.1R7-S3 on EX4300 Series; 16.1 versions prior to 16.1R7 on EX4300 Series; 17.1 versions prior to 17.1R3 on EX4300 Series; 17.2 versions prior to 17.2R3 on EX4300 Series; 17.3 versions prior to 17.3R2-S5, 17.3R3 on EX4300 Series; 17.4 versions prior to 17.4R2 on EX4300 Series; 18.1 versions prior to 18.1R3 on EX4300 Series; 18.2 versions prior to 18.2R2 on EX4300 Series.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2020-1604?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2020-1604?

No fix has been published for CVE-2020-1604 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1604 being exploited?

There is no known exploitation of CVE-2020-1604 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-2020-1604 and fix it if it is affected.

What it is: CVE-2020-1604 is a medium-severity vulnerability in Juniper Junos, published on 15 Jan 2020. 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-2020-1604 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-2020-1604/ (Markdown: https://insights.sbomify.com/CVE-2020-1604/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1604
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1604
- OSV: https://osv.dev/vulnerability/CVE-2020-1604

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1604/
Summaries are generated and may contain mistakes; the official description above is the record.