Find all device files existing anywhere on the system using commands: # find / -type b -print | xargs ls -l > devicelistB # find / -type c -print | xargs ls -l > devicelistC Look at devicelistB and devicelistC files to check the permissions on the device files and directories above the 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.