# CVE-2024-39521: Junos OS Evolved: CLI parameter processing issue allows privilege escalation

> A local authenticated attacker can escalate privileges to root via improper CLI parameter handling in Junos OS Evolved.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jul 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-556v-xwc9-3f54

## What is CVE-2024-39521?

CVE-2024-39521 is a high-severity command injection vulnerability in Juniper Junos Os Evolved, published on 11 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Improper Neutralization of Special Elements vulnerability in Juniper Networks Junos OS Evolved commands allows a local, authenticated attacker with low privileges to escalate their privileges to 'root' leading to a full compromise of the system.

The Junos OS Evolved CLI doesn't properly handle command options in some cases, allowing users which execute specific CLI commands with a crafted set of parameters to escalate their privileges to root on shell level.

This issue affects Junos OS Evolved: 

  *  21.1-EVO versions 21.1R1-EVO and later before 21.2R3-S8-EVO, 
  *  21.4-EVO versions before 21.4R3-S7-EVO,
  *  22.1-EVO versions before 22.1R3-S6-EVO, 
  *  22.2-EVO versions before 22.2R3-EVO,
  *  22.3-EVO versions before 22.3R2-EVO.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2024-39521?

It affects 1 product.


Products: Juniper Junos Os Evolved.

## How do I fix CVE-2024-39521?

No fix has been published for CVE-2024-39521 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-39521 being exploited?

There is no known exploitation of CVE-2024-39521 in the wild and no public exploit code.

## Other vulnerabilities in Juniper Junos Os Evolved

- [CVE-2026-21902](https://insights.sbomify.com/CVE-2026-21902/): Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root (critical 9.3)
- [CVE-2023-28983](https://insights.sbomify.com/CVE-2023-28983/): Junos OS Evolved: Shell Injection vulnerability in the gNOI server (high 8.8)
- [CVE-2025-21599](https://insights.sbomify.com/CVE-2025-21599/): Denial of service in Junos OS Evolved (high 8.7)
- [CVE-2024-47502](https://insights.sbomify.com/CVE-2024-47502/): Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS (high 8.7)
- [CVE-2024-39531](https://insights.sbomify.com/CVE-2024-39531/): Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-39521 and fix it if it is affected.

What it is: CVE-2024-39521 is a high-severity command injection vulnerability in Juniper Junos Os Evolved, published on 11 Jul 2024. 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-2024-39521 in the wild and no public exploit code.

Affected product: Juniper Junos Os Evolved. 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-2024-39521/ (Markdown: https://insights.sbomify.com/CVE-2024-39521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39521
- OSV: https://osv.dev/vulnerability/CVE-2024-39521

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-39521/
Summaries are generated and may contain mistakes; the official description above is the record.