---
title: "HOST-SSH-005 SSH X11 Forwarding Enabled"
canonical: https://openvapt.com/checks/HOST-SSH-005.html
html: https://openvapt.com/checks/HOST-SSH-005.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-SSH-005 SSH X11 Forwarding Enabled

Checks whether SSH forwards graphical X11 sessions.

- Domain: Server
- Severity: Low
- Control category: Secure Configuration
- Fix effort: low
- CVSS v3.1 vector: `CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N`
- CIS Controls v8: 4.1
- NIST CSF 2.0: PR.PS-01
- CWE: CWE-1188
- NIST SP 800-53 Rev. 5: CM-7
- Benchmark topic: SSH server configuration: X11 forwarding (topic only, no benchmark text)

## Why It Matters

Servers rarely need X11. Forwarding it exposes the connecting user's display to anyone with root on the server, and widens the attack surface of sshd.

## How It Detects

Reads X11Forwarding from the effective sshd configuration; 'yes' fails. A risky value set inside a Match block in the config files fails as a conditional finding, with the Match condition in the evidence.

## How to Fix

Set  X11Forwarding no  in /etc/ssh/sshd_config and reload sshd.

## How to Verify

```
sshd -T | grep -i x11forwarding  should print 'no'.
```

## Learn the Theory

- [P2 SSH Security](https://openvapt.com/academy/p2.md)

## References

- [OpenBSD, sshd_config(5) manual page](https://man.openbsd.org/sshd_config)

## Source Code

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

Run it: `openvapt scan --only HOST-SSH-005`. Read it offline: `openvapt explain HOST-SSH-005`.

---

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