# CVE-2024-21594: Junos OS: SRX 5000 Series: Repeated execution of a specific CLI command causes a flowd crash

> An authenticated local attacker can cause a denial of service by repeatedly executing a specific CLI command, crashing the flow processing daemon.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 12 Jan 2024
- **Updated:** 3 Jun 2025
- **Also known as:** GHSA-c34w-cgqm-j3j9

## What is CVE-2024-21594?

CVE-2024-21594 is a medium-severity memory corruption vulnerability in Juniper Junos, published on 12 Jan 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A Heap-based Buffer Overflow vulnerability in the Network Services Daemon (NSD) of Juniper Networks Junos OS allows authenticated, low privileged, local attacker to cause a Denial of Service (DoS).

On an SRX 5000 Series device, when executing a specific command repeatedly, memory is corrupted, which leads to a Flow Processing Daemon (flowd) crash.

The NSD process has to be restarted to restore services.

If this issue occurs, it can be checked with the following command:

user@host> request security policies check
The following log message can also be observed:

Error: policies are out of sync for PFE node<number>.fpc<number>.pic<number>.
This issue affects:

Juniper Networks Junos OS on SRX 5000 Series

  *  All versions earlier than 20.4R3-S6;
  *  21.1 versions earlier than 21.1R3-S5;
  *  21.2 versions earlier than 21.2R3-S4;
  *  21.3 versions earlier than 21.3R3-S3;
  *  21.4 versions earlier than 21.4R3-S3;
  *  22.1 versions earlier than 22.1R3-S1;
  *  22.2 versions earlier than 22.2R3;
  *  22.3 versions earlier than 22.3R2.

Weakness: CWE-787 (Out-of-bounds Write), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2024-21594?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2024-21594?

No fix has been published for CVE-2024-21594 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-21594 being exploited?

There is no known exploitation of CVE-2024-21594 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-2024-21594 and fix it if it is affected.

What it is: CVE-2024-21594 is a medium-severity memory corruption vulnerability in Juniper Junos, published on 12 Jan 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-2024-21594 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-2024-21594/ (Markdown: https://insights.sbomify.com/CVE-2024-21594/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21594
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21594
- OSV: https://osv.dev/vulnerability/CVE-2024-21594

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21594/
Summaries are generated and may contain mistakes; the official description above is the record.