Device files and directories must only be writable by users with a system account or as configured by the vendor.

From Oracle Linux 5 Security Technical Implementation Guide

Associated with: CCI-000225

SV-63229r3_rule Device files and directories must only be writable by users with a system account or as configured by the vendor.

Vulnerability discussion

System device files in writable directories could be modified, removed, or used by an unprivileged user to control system hardware.

Check content

Find all world-writable device files existing anywhere on the system. Procedure: # find / -perm -2 -a \( -type b -o -type c \) > devicelist Check the permissions on the directories above subdirectories containing device files. If any of the device files or their parent directories are world-writable, excepting device files specifically intended to be world-writable such as /dev/null, this is a finding. These world-writable files on installation are intended to be world-writable: /dev/full /dev/null /selinux/null /dev/ptmx /dev/random /dev/tty /dev/vsock /dev/zero /dev/log

Fix text

Remove the world-writable permission from the device file(s). Procedure: # chmod o-w Document all changes.

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