The sshd server must bind the X11 forwarding server to the loopback address.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-233301	SOL-11.1-040331	SV-233301r959010_rule	CCI-000366	medium
Description
As enabling X11 Forwarding on the host can permit a malicious user to secretly open another X11 connection to another remote client during the session and perform unobtrusive activities such as keystroke monitoring, if the X11 services are not required for the system's intended function, they should be disabled or restricted as appropriate to the user's needs. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the DISPLAY environment variable to “localhost”. This prevents remote hosts from connecting to the proxy display.
STIG			Date
Solaris 11 X86 Security Technical Implementation Guide			2025-05-05

Related Frameworks

4 paths across 3 frameworks

NIST 800-531 mapping

CM-6

1.00

DISA · 3 · disa_xccdf · related
DISA · 2025-01-23 · disa_cci_list · equivalent

NIST 800-1712 mappings

3.4.1

1.00

DISA · 3 · disa_xccdf · related
DISA · 2025-01-23 · disa_cci_list · equivalent
NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent

3.4.2

1.00

DISA · 3 · disa_xccdf · related
DISA · 2025-01-23 · disa_cci_list · equivalent
NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent

CCI1 mapping

CCI-000366

1.00

DISA · 3 · disa_xccdf · related

Details

Check Text (C-233301r959010_chk)

Determine if the X11 forwarding server is bound to the loopback address. # grep "^X11UseLocalhost" /etc/ssh/sshd_config If the output of this command is not: X11UseLocalhost yes this is a finding.

Fix Text (F-36460r622216_fix)

The root role is required. Modify the sshd_config file. # vi /etc/ssh/sshd_config Locate the line containing: X11UseLocalhost Change it to: X11UseLocalhost yes Restart the SSH service. # svcadm restart svc:/network/ssh