Verify and Correct Ownership with RPM

An XCCDF Rule

Description

The RPM package management system can check file ownership permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions, which can be found with:

rpm -Va | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }'

run the following command to determine which package owns it:

$ rpm -qf FILENAME

Next, run the following command to reset its permissions to the correct values:

$ sudo rpm --setugids PACKAGENAME

warning alert: Warning

Profiles may require that specific files be owned by root while the default owner defined by the vendor is different. Such files will be reported as a finding and need to be evaluated according to your policy and deployment environment.

warning alert: Warning

This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of packages present on the system. It is not a problem in most cases, but especially systems with a large number of installed packages can be affected.

Rationale

Ownership of binaries and configuration files that is incorrect could allow an unauthorized user to gain privileges that they should not have. The ownership set by the vendor should be maintained. Any deviations from this baseline should be investigated.

ID: xccdf_org.ssgproject.content_rule_rpm_verify_ownership
Severity: High
References: 1 11 12 13 14 15 16 18 3 5 6 9

5.10.4.1

APO01.06 APO11.04 BAI03.05 BAI10.01 BAI10.02 BAI10.03 BAI10.05 DSS05.04 DSS05.07 DSS06.02 MEA02.01

3.3.8 3.4.1

CCI-001494 CCI-001496

4.3.3.3.9 4.3.3.5.8 4.3.3.7.3 4.3.4.3.2 4.3.4.3.3 4.3.4.4.7 4.4.2.1 4.4.2.2 4.4.2.4

SR 2.1 SR 2.10 SR 2.11 SR 2.12 SR 2.8 SR 2.9 SR 5.2 SR 7.6

A.10.1.1 A.11.1.4 A.11.1.5 A.11.2.1 A.12.1.2 A.12.4.1 A.12.4.2 A.12.4.3 A.12.4.4 A.12.5.1 A.12.6.2 A.12.7.1 A.13.1.1 A.13.1.3 A.13.2.1 A.13.2.3 A.13.2.4 A.14.1.2 A.14.1.3 A.14.2.2 A.14.2.3 A.14.2.4 A.6.1.2 A.7.1.1 A.7.1.2 A.7.3.1 A.8.2.2 A.8.2.3 A.9.1.1 A.9.1.2 A.9.2.3 A.9.4.1 A.9.4.4 A.9.4.5

CIP-003-8 R4.2 CIP-003-8 R6 CIP-007-3 R4 CIP-007-3 R4.1 CIP-007-3 R4.2

AU-9(3) CM-6(c) CM-6(d) SI-7 SI-7(1) SI-7(6)

PR.AC-4 PR.DS-5 PR.IP-1 PR.PT-1

Req-11.5

11.5.2

SRG-OS-000256-GPOS-00097 SRG-OS-000257-GPOS-00098 SRG-OS-000278-GPOS-00108
Updated: 8 months ago

- name: Read list of files with incorrect ownership
  command: rpm -Va --nodeps --nosignature --nofiledigest --nosize --nomtime --nordev
    --nocaps --nolinkto --nomode
  register: files_with_incorrect_ownership
  failed_when: files_with_incorrect_ownership.rc > 1
  changed_when: false  check_mode: false
  tags:
  - CJIS-5.10.4.1
  - NIST-800-171-3.3.8
  - NIST-800-171-3.4.1
  - NIST-800-53-AU-9(3)
  - NIST-800-53-CM-6(c)
  - NIST-800-53-CM-6(d)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - NIST-800-53-SI-7(6)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - high_complexity
  - high_severity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy
  - rpm_verify_ownership

- name: Create list of packages
  command: rpm -qf "{{ item }}"
  with_items: '{{ files_with_incorrect_ownership.stdout_lines | map(''regex_findall'',
    ''^[.]+[U|G]+.* (\/.*)'', ''\1'') | map(''join'') | select(''match'', ''(\/.*)'')
    | list | unique }}'
  register: list_of_packages
  changed_when: false
  check_mode: false
  when: (files_with_incorrect_ownership.stdout_lines | length > 0)
  tags:
  - CJIS-5.10.4.1
  - NIST-800-171-3.3.8
  - NIST-800-171-3.4.1
  - NIST-800-53-AU-9(3)
  - NIST-800-53-CM-6(c)
  - NIST-800-53-CM-6(d)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - NIST-800-53-SI-7(6)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - high_complexity
  - high_severity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy
  - rpm_verify_ownership

- name: Correct file ownership with RPM
  command: rpm --setugids '{{ item }}'
  with_items: '{{ list_of_packages.results | map(attribute=''stdout_lines'') | list
    | unique }}'
  when: (files_with_incorrect_ownership.stdout_lines | length > 0)
  tags:
  - CJIS-5.10.4.1
  - NIST-800-171-3.3.8
  - NIST-800-171-3.4.1
  - NIST-800-53-AU-9(3)
  - NIST-800-53-CM-6(c)
  - NIST-800-53-CM-6(d)
  - NIST-800-53-SI-7
  - NIST-800-53-SI-7(1)
  - NIST-800-53-SI-7(6)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - high_complexity
  - high_severity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy
  - rpm_verify_ownership


# Declare array to hold set of RPM packages we need to correct permissions for
declare -A SETPERMS_RPM_DICT

# Create a list of files on the system having permissions different from what
# is expected by the RPM databasereadarray -t FILES_WITH_INCORRECT_PERMS < <(rpm -Va --nofiledigest | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }')

for FILE_PATH in "${FILES_WITH_INCORRECT_PERMS[@]}"
do
        RPM_PACKAGE=$(rpm -qf "$FILE_PATH")
	# Use an associative array to store packages as it's keys, not having to care about duplicates.
	SETPERMS_RPM_DICT["$RPM_PACKAGE"]=1
done

# For each of the RPM packages left in the list -- reset its permissions to the
# correct values
for RPM_PACKAGE in "${!SETPERMS_RPM_DICT[@]}"
do
        rpm --setugids "${RPM_PACKAGE}"
done

Verify and Correct Ownership with RPM

Description

Rationale

Remediation - Ansible

Remediation - Shell Script