Ensure default user umask is 027 or more restrictive

中レベル 2自動cos

説明

The default umask determines the permissions of files created by users. The user creating the file has the discretion of making their files and directories readable by others via the chmod command. Users who wish to allow their files and directories to be readable by others by default may choose a different default umask by inserting the umask command into the standard shell configuration files ( .profile , .bashrc , etc.) in their home directories. Setting a very secure default value for umask ensures that users make a conscious choice about their file permissions. A default umask setting of 077 causes files and directories created by users to not be readable by any other user on the system. A umask of 027 would make files and directories readable by users in the same Unix group, while a umask of 022 would make files readable by every user on the system.

チェック方法

監査方法: シェルコマンド

shell

ok=0; grep -Eiq "^\s*UMASK\s+(0[0-7][2-7]7|[0-7][2-7]7)\b" /etc/login.defs 2>/dev/null && ok=1; grep -REiq "^\s*umask\s+(0[0-7][2-7]7|[0-7][2-7]7)\b" /etc/profile /etc/profile.d /etc/bashrc 2>/dev/null && ok=1; bad=$(grep -RPih "(^|^[^#]*)\s*umask\s+([0-7][0-7][01][0-7]\b|[0-7][0-7][0-7][0-6]\b|[0-7][01][0-7]\b|[0-7][0-7][0-6]\b)" /etc/login.defs /etc/profile /etc/profile.d /etc/bashrc 2>/dev/null); [ $ok -eq 1 ] && [ -z "$bad" ] && echo compliant || echo noncompliant

期待される出力: compliant

修正方法

修正方法: ガイダンスまたは IaC パッチ

Edit the /etc/bash/bashrc, /etc/profile and /etc/profile.d/*.sh files (and the appropriate files for any other shell supported on your system) and add or edit any umask parameters as follows: umask 027

プロパティ

オペレーティングシステム: すべて
タグ: container-optimized-oscos
参照: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.3.4 Ensure default user umask is 027 or more restrictive

このホストをチェック

監査が許可されているマシンで実行してください。スキャンは読み取り専用です。

shell

tmaegis scan --target cos --level 2