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# CIS 5.4.4 Ensure default user umask is 027 or more restrictive (Scored) |
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# |
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# Description |
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# =========== |
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# The default umask determines the permissions of files created by users. |
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# The user creating the file has the discretion of making their files and |
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# directories readable by others via the chmod command. Users who wish to |
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# allow their files and directories to be readable by others by default may |
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# choose a different default umask by inserting the umask command into the |
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# standard shell configuration files ( .profile , .bashrc , etc.) in their |
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# home directories. |
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# |
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# Rationale |
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# ========= |
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# Setting a very secure default value for umask ensures that users make a |
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# conscious choice about their file permissions. A default umask setting of |
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# 077 causes files and directories created by users to not be readable by |
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# any other user on the system. A umask of 027 would make files and |
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# directories readable by users in the same Unix group, while a umask of 022 |
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# would make files readable by every user on the system. |
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# |
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# Audit |
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# ===== |
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# Run the following commands and verify all umask lines returned are 027 or |
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# more restrictive. |
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# |
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# # grep "^umask" /etc/bash.bashrc |
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# umask 027 |
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# # grep "^umask" /etc/profile |
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# umask 027 |
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# |
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# Remediation |
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# =========== |
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# Edit the /etc/bash.bashrc and /etc/profile files (and the appropriate files |
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# for any other shell supported on your system) and add or edit any umask |
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# parameters as follows: |
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# |
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# umask 027 |
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# |
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# Notes |
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# ===== |
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# The audit and remediation in this recommendation apply to bash and shell. |
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# If other shells are supported on the system, it is recommended that their |
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# configuration files also are checked. |
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# |
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# Other methods of setting a default user umask exist however the shell |
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# configuration files are the last run and will override other settings if |
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# they exist therefore our recommendation is to configure in the shell |
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# configuration files. If other methods are in use in your environment they |
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# should be audited and the shell configs should be verified to not override. |
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# |
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parameters: |
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linux: |
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system: |
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shell: |
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umask: "027" |
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