# CVE-2021-28096: Denial of service in n/a

> An attacker can saturate the proxy connection table in Stormshield SNS, causing the proxy to deny new connections.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Jan 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-783c-38cj-6q3h

## What is CVE-2021-28096?

CVE-2021-28096 is a medium-severity denial of service vulnerability in n/a, published on 27 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Stormshield SNS before 4.2.3 (when the proxy is used). An attacker can saturate the proxy connection table. This would result in the proxy denying any new connections.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2021-28096?

It affects 1 product.


Products: Stormshield Stormshield Network Security.

## How do I fix CVE-2021-28096?

No fix has been published for CVE-2021-28096 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-28096 being exploited?

There is no known exploitation of CVE-2021-28096 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-31617](https://insights.sbomify.com/CVE-2021-31617/): Memory corruption in n/a (critical 9.8)
- [CVE-2018-20850](https://insights.sbomify.com/CVE-2018-20850/): Cross-site scripting in n/a (high 8.2)
- [CVE-2025-48707](https://insights.sbomify.com/CVE-2025-48707/): Information disclosure in n/a (high 7.5)
- [CVE-2023-28616](https://insights.sbomify.com/CVE-2023-28616/): Information disclosure in n/a (high 7.5)
- [CVE-2023-47091](https://insights.sbomify.com/CVE-2023-47091/): Integer overflow in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28096 and fix it if it is affected.

What it is: CVE-2021-28096 is a medium-severity denial of service vulnerability in n/a, published on 27 Jan 2022. 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-2021-28096 in the wild and no public exploit code.

Affected product: n/a. 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-2021-28096/ (Markdown: https://insights.sbomify.com/CVE-2021-28096/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28096
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28096
- OSV: https://osv.dev/vulnerability/CVE-2021-28096

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28096/
Summaries are generated and may contain mistakes; the official description above is the record.