The Exchange tarpitting interval must be set.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-221244	EX16-ED-000480	SV-221244r961161_rule	CCI-001308	medium
Description
Tarpitting is the practice of artificially delaying server responses for specific Simple Mail Transfer Protocol (SMTP) communication patterns that indicate high volumes of spam or other unwelcome messages. The intent of tarpitting is to slow down the communication process for spam batches to reduce the cost effectiveness of sending spam and thwart directory harvest attacks. A directory harvest attack is an attempt to collect valid email addresses from a particular organization so the email addresses can be added to a spam database. A program can be written to collect email addresses that return a "Recipient OK" SMTP response and discard all email addresses that return a "User unknown" SMTP response. Tarpitting makes directory harvest attacks too costly to automate efficiently.
STIG			Date
Microsoft Exchange 2016 Edge Transport Server Security Technical Implementation Guide			2024-12-06

Related Frameworks

1 mapping across 3 frameworks

SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

END-08.2Automatic Spam and Phishing Protection Updates

1.00

DISA STIG Benchmark (XCCDF)V2R6intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)
SCF Secure Traceability Relationship Mapping (STRM)2026.2equal to

NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

SI-8(2)Automatic Updates

1.00

DISA STIG Benchmark (XCCDF)V2R6intersects(normalised)
DISA CCI List2025-01-23equal to(normalised)

CCI1 mapping

CCI-001308

1.00

DISA STIG Benchmark (XCCDF)V2R6intersects(normalised)

Details

Check Text (C-221244r961161_chk)

Open the Exchange Management Shell and enter the following command: Get-ReceiveConnector | Select Name, Identity, TarpitInterval For each Receive connector, if the value of "TarpitInterval" is not set to "00:00:05" or greater, this is a finding.

Fix Text (F-22948r411859_fix)

Open the Exchange Management Shell and enter the following command: Set-ReceiveConnector -Identity <'IdentityName'> -TarpitInterval '00:00:05' Note: The <IdentityName> value and the Interval must be in single quotes. Repeat the procedures for each Receive connector.