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Ensure the Group Used by pam_wheel.so Module Exists on System and is Empty

An XCCDF Rule

Description

Ensure that the group referenced by var_pam_wheel_group_for_su variable and used as value for the pam_wheel.so group option exists and has no members. This empty group used by pam_wheel.so in /etc/pam.d/su ensures that no user can run commands with altered privileges through the su command.

warning alert: Warning

Note that this rule just ensures the group exists and has no members. This rule does not configure pam_wheel.so module. The pam_wheel.so module configuration is accomplished by use_pam_wheel_group_for_su rule.

Rationale

The su program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such command is considered a good security practice.

ID
xccdf_org.ssgproject.content_rule_ensure_pam_wheel_group_empty
Severity
Medium
References
Updated



Remediation - Shell Script

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}\n' 'libpam-runtime' 2>/dev/null | grep -q installed; then

var_pam_wheel_group_for_su='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_pam_wheel_group_for_su" use="legacy"/>'



Remediation - Ansible

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - PCI-DSSv4-2.2.6
  - ensure_pam_wheel_group_empty