# CVE-2020-1602: Command injection in Junos OS

> Remote attackers can execute arbitrary code on Juniper devices by sending crafted IPv4 packets to the JDHCPD process when configured in relay mode.

- **Severity:** High 7.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jan 2020
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-4frx-4mrc-562x

## What is CVE-2020-1602?

CVE-2020-1602 is a high-severity command injection vulnerability in Juniper Junos, published on 15 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

When a device using Juniper Network's Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv4 packets who may remotely take over the code execution of the JDHDCP process. This issue affect IPv4 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-1602?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2020-1602?

No fix has been published for CVE-2020-1602 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1602 being exploited?

There is no known exploitation of CVE-2020-1602 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-2020-1602 and fix it if it is affected.

What it is: CVE-2020-1602 is a high-severity command injection vulnerability in Juniper Junos, published on 15 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-1602 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-2020-1602/ (Markdown: https://insights.sbomify.com/CVE-2020-1602/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1602
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1602
- OSV: https://osv.dev/vulnerability/CVE-2020-1602

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1602/
Summaries are generated and may contain mistakes; the official description above is the record.