# CVE-2024-21610: Junos OS: If in a scaled CoS scenario information on CoS state is gathered mgd processes get stuck

> Authenticated low-privilege attackers can cause a limited denial of service by triggering stuck management processes in scaled Class of Service scenarios.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Apr 2024
- **Updated:** 19 May 2025
- **Also known as:** GHSA-6w3v-8x64-r348

## What is CVE-2024-21610?

CVE-2024-21610 is a medium-severity denial of service vulnerability in Juniper Junos, published on 12 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An Improper Handling of Exceptional Conditions vulnerability in the Class of Service daemon (cosd) of Juniper Networks Junos OS allows an authenticated, network-based attacker with low privileges to cause a limited Denial of Service (DoS).

In a scaled CoS scenario with 1000s of interfaces, when specific low privileged commands, received over NETCONF, SSH or telnet, are handled by cosd on behalf of mgd, the respective child management daemon (mgd) processes will get stuck. In case of (Netconf over) SSH this leads to stuck SSH sessions, so that when the connection-limit for SSH is reached, new sessions can't be established anymore. A similar behavior will be seen for telnet etc.

Stuck mgd processes can be monitored by executing the following command:

  user@host> show system processes extensive | match mgd | match sbwait

This issue affects Juniper Networks Junos OS:
  *  All versions earlier than 20.4R3-S9;
  *  21.2 versions earlier than 21.2R3-S7;
  *  21.3 versions earlier than 21.3R3-S5;
  *  21.4 versions earlier than 21.4R3-S5;
  *  22.1 versions earlier than 22.1R3-S4;
  *  22.2 versions earlier than 22.2R3-S3;
  *  22.3 versions earlier than 22.3R3-S2;
  *  22.4 versions earlier than 22.4R3;
  *  23.2 versions earlier than 23.2R1-S2, 23.2R2.

Weakness: CWE-755 (Improper Handling of Exceptional Conditions)

## Which versions are affected by CVE-2024-21610?

It affects 1 product.


Products: Juniper Junos.

## How do I fix CVE-2024-21610?

No fix has been published for CVE-2024-21610 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-21610 being exploited?

There is no known exploitation of CVE-2024-21610 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-2024-21610 and fix it if it is affected.

What it is: CVE-2024-21610 is a medium-severity denial of service vulnerability in Juniper Junos, published on 12 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-21610 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-2024-21610/ (Markdown: https://insights.sbomify.com/CVE-2024-21610/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21610
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21610
- OSV: https://osv.dev/vulnerability/CVE-2024-21610

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21610/
Summaries are generated and may contain mistakes; the official description above is the record.