# CVE-2023-22308: Integer overflow in SoftEther VPN

> An attacker can cause a denial of service in SoftEther VPN by sending a specially crafted network packet that triggers an integer underflow.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-8x86-h5jc-fg6v

## What is CVE-2023-22308?

CVE-2023-22308 is a high-severity vulnerability in SoftEther VPN, published on 12 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An integer underflow vulnerability exists in the vpnserver OvsProcessData functionality of SoftEther VPN 5.01.9674 and 5.02. A specially crafted network packet can lead to denial of service. An attacker can send a malicious packet to trigger this vulnerability.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2023-22308?

It affects 1 product.


Products: Softether Vpn.

## How do I fix CVE-2023-22308?

No fix has been published for CVE-2023-22308 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-22308 being exploited?

There is no known exploitation of CVE-2023-22308 in the wild and no public exploit code.

## Other vulnerabilities in SoftEther VPN

- [CVE-2025-25565](https://insights.sbomify.com/CVE-2025-25565/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-25567](https://insights.sbomify.com/CVE-2025-25567/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-25568](https://insights.sbomify.com/CVE-2025-25568/): Use after free in n/a (critical 9.8)
- [CVE-2023-27395](https://insights.sbomify.com/CVE-2023-27395/): Memory corruption in SoftEther VPN (critical 9.0)
- [CVE-2023-32634](https://insights.sbomify.com/CVE-2023-32634/): Auth bypass in SoftEther VPN (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-22308 and fix it if it is affected.

What it is: CVE-2023-22308 is a high-severity vulnerability in SoftEther VPN, published on 12 Oct 2023. 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-2023-22308 in the wild and no public exploit code.

Affected product: SoftEther VPN. 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-2023-22308/ (Markdown: https://insights.sbomify.com/CVE-2023-22308/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-22308
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-22308
- OSV: https://osv.dev/vulnerability/CVE-2023-22308

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-22308/
Summaries are generated and may contain mistakes; the official description above is the record.