The Exchange email application must not share a partition with another application.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-259704	SRG-APP-000431	EX19-MB-000229	SV-259704r961608_rule	2024-08-22	2

Description
In the same way that added security layers can provide a cumulative positive effect on security posture, multiple applications can provide a cumulative negative effect. A vulnerability and subsequent exploit to one application can lead to an exploit of other applications sharing the same security context. For example, an exploit to a web server process that leads to unauthorized administrative access to the host system can most likely lead to a compromise of all applications hosted by the same system. Email services should be installed on a partition that does not host other applications. Email services should never be installed on a Domain Controller/Directory Services server.

Description

In the same way that added security layers can provide a cumulative positive effect on security posture, multiple applications can provide a cumulative negative effect. A vulnerability and subsequent exploit to one application can lead to an exploit of other applications sharing the same security context. For example, an exploit to a web server process that leads to unauthorized administrative access to the host system can most likely lead to a compromise of all applications hosted by the same system. Email services should be installed on a partition that does not host other applications. Email services should never be installed on a Domain Controller/Directory Services server.

ℹ️ Check
Review the Email Domain Security Plan (EDSP). Determine if the directory Exchange is installed: 1. Open Windows Explorer. 2. Navigate to where Exchange is installed. If Exchange resides on a directory or partition other than that of the operating system and does not have other applications installed (unless approved by the Information System Security Officer [ISSO]), this is not a finding.

✔️ Fix
Update the EDSP with the location of where Exchange is installed. Install Exchange on a dedicated application directory or partition separate than that of the operating system.