---
title: "HOST-SYSD-002 Custom Services Lack Sandboxing"
canonical: https://openvapt.com/checks/HOST-SYSD-002.html
html: https://openvapt.com/checks/HOST-SYSD-002.html
site: OpenVAPT, https://openvapt.com/
license: OpenVAPT Source-Available Licence 1.3, https://openvapt.com/legal/licence-text.html
modified: 2026-10-14
version: 0.1.0-alpha.6
---

# HOST-SYSD-002 Custom Services Lack Sandboxing

Checks whether custom long-running services use systemd's basic sandboxing options.

- Domain: Server
- Severity: Low
- Control category: Secure Configuration
- Fix effort: medium
- CVSS v3.1 vector: `CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N`
- CIS Controls v8: 4.1
- NIST CSF 2.0: PR.PS-01
- CWE: CWE-250, CWE-653
- NIST SP 800-53 Rev. 5: CM-6, SC-39, AC-6
- Benchmark topic: Service isolation (topic only, no benchmark text)

## Why It Matters

systemd can confine a service with a few lines: block privilege gain through setuid programs, mount the operating system read-only, give it a private /tmp and hide home directories. These limit what an attacker can do after exploiting the service, at almost no cost.

## How It Detects

For each long-running service unit in /etc/systemd/system, merges drop-ins and checks for NoNewPrivileges=yes, ProtectSystem=strict (or full/yes), PrivateTmp=yes and ProtectHome=yes (or read-only/tmpfs). Lists the missing settings per unit.

## How to Fix

Add the missing lines with systemctl edit <unit> (a drop-in), for example NoNewPrivileges=yes, ProtectSystem=strict, ReadWritePaths=/var/lib/<app>, PrivateTmp=yes, ProtectHome=yes. Restart the service and test it; add ReadWritePaths= for every folder the app must write. systemd-analyze security <unit> suggests further options.

## How to Verify

```
systemd-analyze security <unit>  shows a lower exposure score, and the service still works.
```

## Learn the Theory

- [P11 Service Hardening With systemd](https://openvapt.com/academy/p11.md)

## References

- [systemd.exec(5), execution environment configuration](https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html)
- [systemd-analyze(1), security verb](https://www.freedesktop.org/software/systemd/man/latest/systemd-analyze.html)

## Source Code

https://github.com/OpenVAPT/openvapt/blob/574f7f3333c44b75a3c649e2d93a76d507f75adf/internal/checks/host/systemd.go

Run it: `openvapt scan --only HOST-SYSD-002`. Read it offline: `openvapt explain HOST-SYSD-002`.

---

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