Remove Rsh Trust Files

An XCCDF Rule

Description

The files /etc/hosts.equiv and ~/.rhosts (in each user's home directory) list remote hosts and users that are trusted by the local system when using the rshd daemon. To remove these files, run the following command to delete them from any location:

$ sudo rm /etc/hosts.equiv

$ rm ~/.rhosts

Rationale

This action is only meaningful if .rhosts support is permitted through PAM. Trust files are convenient, but when used in conjunction with the R-services, they can allow unauthenticated access to a system.

ID: xccdf_org.ssgproject.content_rule_no_rsh_trust_files
Severity: High
References: 11 12 14 15 3 8 9

APO13.01 BAI10.01 BAI10.02 BAI10.03 BAI10.05 DSS01.04 DSS05.02 DSS05.03 DSS05.05 DSS06.06

CCI-001436

164.308(a)(4)(i) 164.308(b)(1) 164.308(b)(3) 164.310(b) 164.312(e)(1) 164.312(e)(2)(ii)

4.3.3.5.1 4.3.3.5.2 4.3.3.5.3 4.3.3.5.4 4.3.3.5.5 4.3.3.5.6 4.3.3.5.7 4.3.3.5.8 4.3.3.6.1 4.3.3.6.2 4.3.3.6.3 4.3.3.6.4 4.3.3.6.5 4.3.3.6.6 4.3.3.6.7 4.3.3.6.8 4.3.3.6.9 4.3.3.7.1 4.3.3.7.2 4.3.3.7.3 4.3.3.7.4 4.3.4.3.2 4.3.4.3.3

SR 1.1 SR 1.10 SR 1.11 SR 1.12 SR 1.13 SR 1.2 SR 1.3 SR 1.4 SR 1.5 SR 1.6 SR 1.7 SR 1.8 SR 1.9 SR 2.1 SR 2.2 SR 2.3 SR 2.4 SR 2.5 SR 2.6 SR 2.7 SR 3.1 SR 3.5 SR 3.8 SR 4.1 SR 4.3 SR 5.1 SR 5.2 SR 5.3 SR 7.1 SR 7.6

A.11.2.6 A.12.1.2 A.12.5.1 A.12.6.2 A.13.1.1 A.13.2.1 A.14.1.3 A.14.2.2 A.14.2.3 A.14.2.4 A.6.2.1 A.6.2.2 A.9.1.2

CM-6(a) CM-7(a) CM-7(b)

PR.AC-3 PR.IP-1 PR.PT-3 PR.PT-4
Updated: about 1 year ago

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)  - NIST-800-53-CM-7(b)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - no_rsh_trust_files
  - restrict_strategy

- name: Detect .rhosts files in users home directories
  find:
    paths:
    - /root
    - /home
    recurse: true
    patterns: .rhosts
    hidden: true
    file_type: file
  check_mode: false
  register: rhosts_locations
  when: '"rsh-server" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - no_rsh_trust_files
  - restrict_strategy

- name: Remove .rhosts files
  file:
    path: '{{ item }}'
    state: absent
  with_items: '{{ rhosts_locations.files | map(attribute=''path'') | list }}'
  when:
  - '"rsh-server" in ansible_facts.packages'
  - rhosts_locations is success
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - no_rsh_trust_files
  - restrict_strategy

- name: Remove /etc/hosts.equiv file
  file:
    path: /etc/hosts.equiv
    state: absent
  when: '"rsh-server" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - no_rsh_trust_files
  - restrict_strategy

# Remediation is applicable only in certain platforms
if rpm --quiet -q rsh-server; then

find /root -xdev -type f -name ".rhosts" -exec rm -f {} \;
find /home -maxdepth 2 -xdev -type f -name ".rhosts" -exec rm -f {} \;
rm -f /etc/hosts.equiv
else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remove Rsh Trust Files

Description

Rationale

Remediation - Ansible

Remediation - Shell Script