8.1.2 Remove OS Information from Login Warning Banners - /etc/motd

Information

Unix-based systems have typically displayed information about the OS release and patch level upon logging in to the system. This information can be useful to developers who are developing software for a particular OS platform. If mingetty(8) supports the following options, they display operating system information:

m - machine architecture (uname -m) r - operating system release (uname -r) s - operating system name v - operating system version (uname -v)

Rationale:

Displaying OS and patch level information in login banners also has the side effect of providing detailed system information to attackers attempting to target specific exploits of a system. Authorized users can easily get this information by running the 'uname -a' command once they have logged in.

Solution

Edit the /etc/issue, /etc/motd, and /etc/issue.net files with the appropriate contents according to your site policy, remove any instances of m ,r ,s ,v, or references to the OS platform

Default Value:

OS Default: No

See Also

https://workbench.cisecurity.org/files/3096

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, CSCv6|3.1, CSCv7|5.1

Plugin: Unix

Control ID: d0d8e2d490ca654fc389f32a7dae1a555e20d8a84ae106fc3ce1f3f4891b1b37