# CVE-2018-18856: Command injection in n/a

> Local attackers can execute arbitrary OS commands as root via an unprotected XPC service in the LiquidVPN macOS client, leading to 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:** No
- **Published:** 20 Nov 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-xmgg-82f8-jrc5

## What is CVE-2018-18856?

CVE-2018-18856 is a high-severity command injection vulnerability in n/a, published on 20 Nov 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Multiple local privilege escalation vulnerabilities have been identified in the LiquidVPN client through 1.37 for macOS. An attacker can communicate with an unprotected XPC service and directly execute arbitrary OS commands as root or load a potentially malicious kernel extension because com.smr.liquidvpn.OVPNHelper uses the system function to execute the "openvpncmd" parameter as a shell command.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2018-18856?

It affects 1 product.


Products: Liquidvpn Liquidvpn.

## How do I fix CVE-2018-18856?

No fix has been published for CVE-2018-18856 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-18856 being exploited?

There is no known exploitation of CVE-2018-18856 in the wild and no public exploit code.

Public exploit code:

- LiquidVPN 1.36 / 1.37 - Privilege Escalation (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2018-18857](https://insights.sbomify.com/CVE-2018-18857/): Multiple local privilege escalation vulnerabilities have been identified in the LiquidVPN client through 1.37 for macOS. (high 7.8)
- [CVE-2018-18858](https://insights.sbomify.com/CVE-2018-18858/): Command injection in n/a (high 7.8)
- [CVE-2018-18859](https://insights.sbomify.com/CVE-2018-18859/): Command injection in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-18856 and fix it if it is affected.

What it is: CVE-2018-18856 is a high-severity command injection vulnerability in n/a, published on 20 Nov 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-2018-18856 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-2018-18856/ (Markdown: https://insights.sbomify.com/CVE-2018-18856/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18856
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18856
- OSV: https://osv.dev/vulnerability/CVE-2018-18856

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-18856/
Summaries are generated and may contain mistakes; the official description above is the record.