# CVE-2018-4006: Privilege escalation in Shimo VPN

> A local attacker can exploit a file write vulnerability in the Shimo VPN helper service to escalate privileges to root.

- **Severity:** Critical 9.3 (`CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Apr 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-77gm-qcq9-fqc2

## What is CVE-2018-4006?

CVE-2018-4006 is a critical vulnerability in Shimo VPN, published on 17 Apr 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An exploitable privilege escalation vulnerability exists in the Shimo VPN 4.1.5.1 helper service in the writeConfig functionality. A non-root user is able to write a file anywhere on the system. A user with local access can use this vulnerability to raise their privileges to root. An attacker would need local access to the machine to exploit it successfully.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-4006?

It affects 1 product.


Products: Shimovpn Shimo Vpn.

## How do I fix CVE-2018-4006?

No fix has been published for CVE-2018-4006 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-4006 being exploited?

There is no known exploitation of CVE-2018-4006 in the wild and no public exploit code.

## Other vulnerabilities in Shimo VPN

- [CVE-2018-4005](https://insights.sbomify.com/CVE-2018-4005/): Privilege escalation in Shimo VPN (critical 9.3)
- [CVE-2018-4008](https://insights.sbomify.com/CVE-2018-4008/): Privilege escalation in Shimo VPN (critical 9.3)
- [CVE-2018-4007](https://insights.sbomify.com/CVE-2018-4007/): Privilege escalation in Shimo VPN (critical 9.0)
- [CVE-2018-4009](https://insights.sbomify.com/CVE-2018-4009/): Privilege escalation in Shimo VPN (high 8.8)
- [CVE-2018-4004](https://insights.sbomify.com/CVE-2018-4004/): Privilege escalation in Shimo VPN (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-4006 and fix it if it is affected.

What it is: CVE-2018-4006 is a critical vulnerability in Shimo VPN, published on 17 Apr 2019. 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-2018-4006 in the wild and no public exploit code.

Affected product: Shimo 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-2018-4006/ (Markdown: https://insights.sbomify.com/CVE-2018-4006/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-4006
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-4006
- OSV: https://osv.dev/vulnerability/CVE-2018-4006

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-4006/
Summaries are generated and may contain mistakes; the official description above is the record.