Guide to the Secure Configuration of SUSE Linux Enterprise 11

with profile Server Baseline
This profile is for SUSE Enterprise Linux 11 acting as a server.
This guide presents a catalog of security-relevant configuration settings for SUSE Linux Enterprise 11. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the scap-security-guide package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.

Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.
Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.
Profile TitleServer Baseline
Profile IDxccdf_org.ssgproject.content_profile_server

Revision History

Current version: 0.1.41

  • draft (as of 2018-10-09)

Platforms

  • cpe:/o:suse:linux_enterprise_server:11

Table of Contents

  1. System Settings
    1. File Permissions and Masks

Checklist

contains 3 rules

System Settings   [ref]group

Contains rules that check correct system settings.

contains 3 rules

File Permissions and Masks   [ref]group

Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access.

Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn.

The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Red Hat Enterprise Linux 7 installations:

$ mount -t xfs | awk '{print $3}'
For any systems that use a different local filesystem type, modify this command as appropriate.

contains 3 rules

Verify Permissions on Important Files and Directories   [ref]group

Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.

contains 3 rules
contains 3 rules

Verify Group Who Owns passwd File   [ref]rule

To properly set the group owner of /etc/passwd, run the command:

$ sudo chgrp root /etc/passwd

Rationale:

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Severity:  medium

References:  6.1.2, 5.5.2.2, AC-6, Req-8.7.c

Remediation Shell script:   (show)

Complexity:low
Disruption:low
Strategy:configure

chgrp 0 /etc/passwd
Remediation Ansible snippet:   (show)

Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists

- name: Ensure group owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    group: 0
  when: file_exists.stat.exists
  tags:
    - file_groupowner_etc_passwd
    - medium_severity
    - configure_strategy
    - low_complexity
    - low_disruption
    - NIST-800-53-AC-6
    - PCI-DSS-Req-8.7.c
    - CJIS-5.5.2.2

Verify User Who Owns passwd File   [ref]rule

To properly set the owner of /etc/passwd, run the command:

$ sudo chown root /etc/passwd 

Rationale:

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Severity:  medium

References:  6.1.2, 5.5.2.2, AC-6, Req-8.7.c

Remediation Shell script:   (show)

Complexity:low
Disruption:low
Strategy:configure

chown 0 /etc/passwd
Remediation Ansible snippet:   (show)

Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists

- name: Ensure owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    owner: 0
  when: file_exists.stat.exists
  tags:
    - file_owner_etc_passwd
    - medium_severity
    - configure_strategy
    - low_complexity
    - low_disruption
    - NIST-800-53-AC-6
    - PCI-DSS-Req-8.7.c
    - CJIS-5.5.2.2

Verify Permissions on passwd File   [ref]rule

To properly set the permissions of /etc/passwd, run the command:

$ sudo chmod 0644 /etc/passwd

Rationale:

If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.

Severity:  medium

References:  6.1.2, 5.5.2.2, AC-6, Req-8.7.c

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