Which of the following best describes the EternalBlue explot?

$1.$

EternalBlue is an exploit of Microsoft's implementation of their Server Message Block $($SMB$)$ protocol.

$2.$

EternalBlue is an exploit of Google Chrome Browser software that allows a remote attacker to compromise vulnerable system.

$3.$

EternalBlue is an exploit of a boundary error within the Microsoft Windows Desktop Windows Manager $($DWM$)$ Core Library

$4.$

EternalBlue is an exploit in PaperCut print management software that allows attackers to bypass authentication and execute arbitrary code as SYSTEM on vulnerable targets.