# CVE-2018-9336: Use after free in n/a

> A local attacker can trigger a double-free in the OpenVPN interactive service, causing denial of service or potential privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** Yes
- **Published:** 1 May 2018
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2018-9336, GHSA-9p34-3252-9gh9, MGASA-2018-0329, SUSE-SU-2018:1888-1

## What is CVE-2018-9336?

CVE-2018-9336 is a high-severity use after free vulnerability in Slackware Slackware Linux, published on 1 May 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

openvpnserv.exe (aka the interactive service helper) in OpenVPN 2.4.x before 2.4.6 allows a local attacker to cause a double-free of memory by sending a malformed request to the interactive service. This could cause a denial-of-service through memory corruption or possibly have unspecified other impact including privilege escalation.

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2018-9336?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `openvpn` | SUSE:Linux Enterprise Module for Basesystem 15 | All versions | 2.4.3-5.3.19 |

Products: Openvpn Openvpn, Slackware Slackware Linux.

## How do I fix CVE-2018-9336?

Upgrade to a fixed version.

## Is CVE-2018-9336 being exploited?

There is no known exploitation of CVE-2018-9336 in the wild and no public exploit code.

## Other vulnerabilities in Slackware Slackware Linux

- [CVE-2025-12106](https://insights.sbomify.com/CVE-2025-12106/): Memory corruption in OpenVPN (critical 9.1)
- [CVE-2024-5594](https://insights.sbomify.com/CVE-2024-5594/): Information disclosure in OpenVPN (critical 9.1)
- [CVE-2018-7544](https://insights.sbomify.com/CVE-2018-7544/): Cross-site request forgery in n/a (critical 9.1)
- [CVE-2006-1629](https://insights.sbomify.com/CVE-2006-1629/): Code injection in n/a (critical 9.0)
- [CVE-2024-4877](https://insights.sbomify.com/CVE-2024-4877/): Privilege escalation in OpenVPN (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-9336 and fix it if it is affected.

What it is: CVE-2018-9336 is a high-severity use after free vulnerability in Slackware Slackware Linux, published on 1 May 2018. 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-2018-9336 in the wild and no public exploit code.

Affected product: Slackware Slackware Linux. 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-2018-9336/ (Markdown: https://insights.sbomify.com/CVE-2018-9336/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-9336
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-9336
- OSV: https://osv.dev/vulnerability/CVE-2018-9336

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-9336/
Summaries are generated and may contain mistakes; the official description above is the record.