Ensure Logs Sent To Remote Host

An XCCDF Rule

Description

To configure rsyslog to send logs to a remote log server, open /etc/rsyslog.conf and read and understand the last section of the file, which describes the multiple directives necessary to activate remote logging. Along with these other directives, the system can be configured to forward its logs to a particular log server by adding or correcting one of the following lines, substituting appropriately. The choice of protocol depends on the environment of the system; although TCP and RELP provide more reliable message delivery, they may not be supported in all environments.
To use UDP for log message delivery:

*.* @

To use TCP for log message delivery:

*.* @@

To use RELP for log message delivery:

*.* :omrelp:

There must be a resolvable DNS CNAME or Alias record set to "" for logs to be sent correctly to the centralized logging utility.

warning alert: Functionality Warning

It is important to configure queues in case the client is sending log messages to a remote server. If queues are not configured, the system will stop functioning when the connection to the remote server is not available. Please consult Rsyslog documentation for more information about configuration of queues. The example configuration which should go into /etc/rsyslog.conf can look like the following lines:

$ActionQueueType LinkedList
$ActionQueueFileName queuefilename
$ActionQueueMaxDiskSpace 1g
$ActionQueueSaveOnShutdown on
$ActionResumeRetryCount -1

Rationale

A log server (loghost) receives syslog messages from one or more systems. This data can be used as an additional log source in the event a system is compromised and its local logs are suspect. Forwarding log messages to a remote loghost also provides system administrators with a centralized place to view the status of multiple hosts within the enterprise.

ID: xccdf_org.ssgproject.content_rule_rsyslog_remote_loghost
Severity: Medium
References: BP28(R7) NT12(R5) NT28(R43)

1 13 14 15 16 2 3 5 6

APO11.04 APO13.01 BAI03.05 BAI04.04 DSS05.04 DSS05.07 MEA02.01

CCI-000136 CCI-000366 CCI-001348 CCI-001851

164.308(a)(1)(ii)(D) 164.308(a)(5)(ii)(B) 164.308(a)(5)(ii)(C) 164.308(a)(6)(ii) 164.308(a)(8) 164.310(d)(2)(iii) 164.312(b) 164.314(a)(2)(i)(C) 164.314(a)(2)(iii)

4.3.3.3.9 4.3.3.5.8 4.3.4.4.7 4.4.2.1 4.4.2.2 4.4.2.4

SR 2.10 SR 2.11 SR 2.12 SR 2.8 SR 2.9 SR 7.1 SR 7.2

0988 1405

A.12.1.3 A.12.4.1 A.12.4.2 A.12.4.3 A.12.4.4 A.12.7.1 A.17.2.1

CIP-003-8 R5.2 CIP-004-6 R3.3

AU-4(1) AU-9(2) CM-6(a)

PR.DS-4 PR.PT-1

FAU_GEN.1.1.c

SRG-OS-000342-GPOS-00133 SRG-OS-000479-GPOS-00224 SRG-OS-000480-GPOS-00227

SLES-15-010580

4.2.1.5

CCE-85552-8

SV-234865r854211_rule
Updated: about 1 year ago

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

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

# If the key exists, comment it. Otherwise do nothing# We search for the key string followed by a blank space,
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*[[:blank:]]" "/etc/rsyslog.conf"; then
    LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*[[:blank:]].*/#&/gi" "/etc/rsyslog.conf"
fi
# If the key exists, comment it. Otherwise do nothing
# We search for the key string followed by a blank space,
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*[[:blank:]]" "/etc/rsyslog.d/*.conf"; then
    LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*[[:blank:]].*/#&/gi" "/etc/rsyslog.d/*.conf"
fi
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^\*\.\*")

# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "@@$rsyslog_remote_loghost_address"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*\\>" "/etc/rsyslog.d/remote.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*\\>.*/$escaped_formatted_output/gi" "/etc/rsyslog.d/remote.conf"
else
    if [[ -s "/etc/rsyslog.d/remote.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/rsyslog.d/remote.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/rsyslog.d/remote.conf"
    fi
    cce="CCE-85552-8"
    printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/rsyslog.d/remote.conf" >> "/etc/rsyslog.d/remote.conf"
    printf '%s\n' "$formatted_output" >> "/etc/rsyslog.d/remote.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

- name: XCCDF Value rsyslog_remote_loghost_address # promote to variable
  set_fact:
    rsyslog_remote_loghost_address: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_rsyslog_remote_loghost_address" use="legacy"/>
  tags:
    - always
- name: Check for duplicate values in master configuration
  ansible.builtin.lineinfile:
    path: /etc/rsyslog.conf
    create: false
    regexp: ^\*\.\*\s+.*$
    state: absent
  changed_when: false
  register: dupes_master
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85552-8
  - DISA-STIG-SLES-15-010580
  - NIST-800-53-AU-4(1)
  - NIST-800-53-AU-9(2)
  - NIST-800-53-CM-6(a)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - rsyslog_remote_loghost

- name: Collect all config rsyslog files which configure remote logger
  ansible.builtin.find:
    paths: /etc/rsyslog.d/
    contains: ^\*\.\*\s+.*$
    patterns: '*.conf'
  register: rsyslog_dropin_config_files
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85552-8
  - DISA-STIG-SLES-15-010580
  - NIST-800-53-AU-4(1)
  - NIST-800-53-AU-9(2)
  - NIST-800-53-CM-6(a)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - rsyslog_remote_loghost

- name: Deduplicate values from rsyslog dropin configuration
  ansible.builtin.lineinfile:
    path: '{{ item.path }}'
    create: false
    regexp: ^\*\.\*\s+.*$
    state: absent
  loop: '{{  rsyslog_dropin_config_files.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85552-8
  - DISA-STIG-SLES-15-010580
  - NIST-800-53-AU-4(1)
  - NIST-800-53-AU-9(2)
  - NIST-800-53-CM-6(a)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - rsyslog_remote_loghost

- name: Set rsyslog remote loghost
  lineinfile:
    dest: /etc/rsyslog.d/remote.conf
    regexp: ^\*\.\*\s+.*$
    line: '*.* @@{{ rsyslog_remote_loghost_address }}'
    create: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-85552-8
  - DISA-STIG-SLES-15-010580
  - NIST-800-53-AU-4(1)
  - NIST-800-53-AU-9(2)
  - NIST-800-53-CM-6(a)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - rsyslog_remote_loghost

Ensure Logs Sent To Remote Host

Description

Rationale

Remediation - Shell Script

Remediation - Ansible