The operating system must employ strong authenticators in the establishment of non-local maintenance and diagnostic sessions.

From Apple OS X 10.10 (Yosemite) Workstation Security Technical Implementation Guide

Associated with: CCI-000877

SV-74107r1_rule The operating system must employ strong authenticators in the establishment of non-local maintenance and diagnostic sessions.

Vulnerability discussion

The telnet service must be disabled, as it sends all data, including the user's password, in a clear text form that can be easily intercepted and read. Passwords need to be protected at all times and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Disabling telnet is one way to mitigate this risk. Administrators should be instructed to use an alternate service for remote access sessions that uses encryption, such as SSH.

Check content

To check if the 'telnet' service is disabled, use the following command: sudo launchctl print-disabled system | grep com.apple.telnetd If the results do not show the following: "com.apple.telnetd" => true this is a finding.

Fix text

To disable the 'telnet' service, run the following command: sudo launchctl disable system/com.apple.telnetd The system may need to be restarted for the update to take effect.

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