5.5 Use a separate timestamp for each user/tty combo

Information

Using tty tickets ensures that a user must enter the sudo password in each Terminal session.

With sudo versions 1.8 and higher, introduced in 10.12, the default value is to have tty tickets for each interface so that root access is limited to a specific terminal. The default configuration can be overwritten or not configured correctly on earlier versions of macOS.

Rationale:

In combination with removing the sudo timeout grace period a further mitigation should be in place to reduce the possibility of a background process using elevated rights when a user elevates to root in an explicit context or tty.

Additional mitigation should be in place to reduce the risk of privilege escalation of background processes.

Impact:

This control should have no user impact. Developers or installers may have issues if background processes are spawned with different interfaces than where sudo was executed.

Solution

Edit the /etc/sudoers file with visudo and remove !tty_tickets from any Defaults line.
If there is a file in the /etc/sudoers.d/ folder that contains Defaults !tty_tickets, edit the file and remove !tty_tickets from any Defaults line.

Default Value:

If no value is set, the default value of tty_tickets enabled will be used.

Additional Information:

https://github.com/jorangreef/sudo-prompt/issues/33

See Also

https://workbench.cisecurity.org/files/3013

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-3(7)

Plugin: Unix

Control ID: 14940162a09e507de71dba38116e9a82bf3d469d04f63acdda308ae0d07eb8b8