Ensure permissions on SSH private host key files are configured

MittelStufe 1Automatisiertcos

Beschreibung

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

So wird geprüft

Prüfmethode: Shell-Befehl

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

Erwartete Ausgabe: compliant

So wird behoben

Behebungsmethode: Anleitung oder Infrastruktur-Patch

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 {} \;

Eigenschaften

Betriebssysteme: Beliebig
Tags: access-controlcontainer-optimized-oscoscryptossh
Referenz: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.2 Ensure permissions on SSH private host key files are configured

Diesen Host prüfen

Führen Sie dies auf einem Rechner aus, den Sie prüfen dürfen. Der Scan ist schreibgeschützt.

shell

tmaegis scan --target cos