Extensions that are approved for use must be allowlisted if used.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
low	V-235755	SRG-APP-000386	EDGE-00-000042	SV-235755r961479_rule	2024-09-13	2

Description
By default, all extensions are allowed. However, if all extensions are blocked by setting the "ExtensionInstallBlockList" policy to "*," users can only install extensions defined in this policy.

ℹ️ Check
This requirement for "Allow specific extensions to be installed" is not required; this is optional. The policy value for "Computer Configuration/Administrative Templates/Microsoft Edge/Extensions/Allow specific extensions to be installed" must be set to "Enabled". Use the Windows Registry Editor to navigate to the following key: HKLM\SOFTWARE\Policies\Microsoft\Edge "ExtensionInstallAllowlist" must be set as follows: HKLM\SOFTWARE\Policies\Microsoft\Edge\ExtensionInstallAllowlist\1 = "extension_id1" HKLM\SOFTWARE\Policies\Microsoft\Edge\ExtensionInstallAllowlist\2 = "extension_id2" If configured, the list of extensions for which Microsoft Edge allows to be installed may be allowlisted.

ℹ️ Check

This requirement for "Allow specific extensions to be installed" is not required; this is optional. The policy value for "Computer Configuration/Administrative Templates/Microsoft Edge/Extensions/Allow specific extensions to be installed" must be set to "Enabled". Use the Windows Registry Editor to navigate to the following key: HKLM\SOFTWARE\Policies\Microsoft\Edge "ExtensionInstallAllowlist" must be set as follows: HKLM\SOFTWARE\Policies\Microsoft\Edge\ExtensionInstallAllowlist\1 = "extension_id1" HKLM\SOFTWARE\Policies\Microsoft\Edge\ExtensionInstallAllowlist\2 = "extension_id2" If configured, the list of extensions for which Microsoft Edge allows to be installed may be allowlisted.

✔️ Fix
Set the policy value for "Computer Configuration/Administrative Templates/Microsoft Edge/Extensions/Allow specific extensions to be installed" to "Enabled". A list of allowlisted extensions may then be specified.