STIGQter: STIG Summary: Oracle Linux 9 Security Technical Implementation Guide Version: 1 Release: 6 Benchmark Date: 01 Jul 2026:

OL 9 must disable the use of user namespaces.

DISA Rule

SV-271727r1091893_rule

Vulnerability Number

V-271727

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

OL09-00-002370

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

Configure OL 9 to disable the use of user namespaces by adding the following line to a file, in the "/etc/sysctl.d" directory:

Note: User namespaces are used primarily for Linux containers. If containers are in use, this requirement is Not Applicable.

user.max_user_namespaces = 0

The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command:

$ sudo sysctl --system

Check Contents

Note: User namespaces are used primarily for Linux containers. If containers are in use, this requirement is Not Applicable.

Verify that OL 9 disables the use of user namespaces with the following commands:

$ sysctl user.max_user_namespaces
user.max_user_namespaces = 0

If the returned line does not have a value of "0", or a line is not returned, this is a finding.

Vulnerability Number

V-271727

Documentable

False

Rule Version

OL09-00-002370

Severity Override Guidance

Note: User namespaces are used primarily for Linux containers. If containers are in use, this requirement is Not Applicable.

Verify that OL 9 disables the use of user namespaces with the following commands:

$ sysctl user.max_user_namespaces
user.max_user_namespaces = 0

If the returned line does not have a value of "0", or a line is not returned, this is a finding.

Check Content Reference

M

Target Key

5680