Ensure permissions on SSH private host key files are configured

СреднийУровень 1Автоматическаяcos

Описание

An SSH private key is one of two files used in SSH public key authentication. In this authentication method, the possession of the private key is proof of identity. Only a private key that corresponds to a public key will be able to authenticate successfully. The private keys need to be stored and handled carefully, and no copies of the private key should be distributed. If an unauthorized user obtains the private SSH host key file, the host could be impersonated

Как проверяется

Метод проверки: Команда оболочки

shell

alt0() { o=$(bash -c 'find /etc/ssh -xdev -type f -name '"'"'ssh_host_*_key'"'"' -exec stat {} \;' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_rsa_key’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_rsa_key’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 1679 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 1679 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8628138 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8628138 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)' || { echo step1: missing 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: 2018-10-22 18:24:56.861750616 +0000' || { echo step1: missing 'Access: 2018-10-22 18:24:56.861750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.861750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.861750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.873750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.873750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Birth: -' || { echo step1: missing 'Birth: -'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_ecdsa_key’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_ecdsa_key’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 227 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 227 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631760 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631760 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)' || { echo step1: missing 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: 2018-10-22 18:24:56.897750616 +0000' || { echo step1: missing 'Access: 2018-10-22 18:24:56.897750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.897750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.897750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.905750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.905750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Birth: -' || { echo step1: missing 'Birth: -'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_ed25519_key’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_ed25519_key’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 387 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 387 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631762 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631762 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)' || { echo step1: missing 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: 2018-10-22 18:24:56.945750616 +0000' || { echo step1: missing 'Access: 2018-10-22 18:24:56.945750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.945750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.945750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.957750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.957750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Birth: -' || { echo step1: missing 'Birth: -'; return 1; }; }; if alt0; then echo compliant; fi

Ожидаемый вывод: compliant

Как исправляется

Метод исправления: Рекомендация или патч инфраструктуры

Run the following commands to set ownership and permissions on the private SSH host key files # find /etc/ssh -xdev -type f -name 'ssh_host_*_key' -exec chown root:root {} \; # find /etc/ssh -xdev -type f -name 'ssh_host_*_key' -exec chmod 0600 {} \;

Свойства

Операционные системы: Любая
Теги: access-controlcontainer-optimized-oscoscryptossh
Источник: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.2 Ensure permissions on SSH private host key files are configured

Проверить этот хост

Выполните команду на компьютере, аудит которого вам разрешён. Сканирование работает только на чтение.

shell

tmaegis scan --target cos