.Net applications that invoke NetFx40_LegacySecurityPolicy must apply previous versions of .NET STIG guidance.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-30937	APPNET0064	SV-40979r1_rule	DCSL-1	Low

Description
CAS policy is .NET runtime version-specific. In .NET Framework version 4, CAS policy is disabled by default however; it can be re-enabled by using the NetFx40_LegacySecurityPolicy setting on a per application basis. When invoking the NetFx40_LegacySecurityPolicy setting in .NET 4, earlier versions of the .NET Framework CAS policy will become active therefore previous .NET STIG guidance that applies to the reactivated versions must also be applied. Failure to apply applicable versions of STIG guidance can result in the loss of system confidentiality, integrity or availability.

Description

CAS policy is .NET runtime version-specific. In .NET Framework version 4, CAS policy is disabled by default however; it can be re-enabled by using the NetFx40_LegacySecurityPolicy setting on a per application basis. When invoking the NetFx40_LegacySecurityPolicy setting in .NET 4, earlier versions of the .NET Framework CAS policy will become active therefore previous .NET STIG guidance that applies to the reactivated versions must also be applied. Failure to apply applicable versions of STIG guidance can result in the loss of system confidentiality, integrity or availability.

STIG	Date
Microsoft Dot Net Framework 4.0 STIG	2017-06-14

Details

Check Text ( C-39675r5_chk )
Open Windows explorer and search for all *.exe.config files. Search each file for NetFx40_LegacySecurityPolicy enabled="true". If the .NET application configuration file utilizes the legacy policy element and .NET STIG guidance that covers these legacy versions has not been applied, this is a finding.

Fix Text (F-34827r7_fix)
Apply the .NET Framework Security Checklist for .Net versions 1 through 3.5 when utilizing the NetFx40_LegacySecurityPolicy setting.