The Exchange Sender Reputation filter must identify the spam block level.

From MS Exchange 2013 Edge Transport Server Security Technical Implementation Guide

Associated with: CCI-001308

SV-84495r1_rule The Exchange Sender Reputation filter must identify the spam block level.

Vulnerability discussion

By performing filtering at the perimeter, up to 90 percent of spam, malware, and other undesirable messages are eliminated from the message stream rather than admitting them into the mail server environment. Sender Reputation is antispam functionality that blocks messages according to many characteristics of the sender. Sender Reputation relies on persisted data about the sender to determine what action, if any, to take on an inbound message. This setting enables the threshold at which an email will be considered spam.

Check content

Open the Exchange Management Shell and enter the following command: Get-SenderReputationConfig | Select Name, SrlBlockThreshold If the value of SrlBlockThreshold is not set to 6, this is a finding. or If the value of SrlBlockThreshold is set to a value other than 6 and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix text

Open the Exchange Management Shell and enter the following command: Set-SenderReputationConfig -SrlBlockThreshold 6 or The value as identified by the EDSP that has obtained a signoff with risk acceptance.

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