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AWS AWSEC2 medium security documentation change

Service: AWSEC2 · 2025-05-16 · Security-related medium

File: AWSEC2/latest/UserGuide/win-start-fast-launch-prereqs.md

Summary

Updated prerequisites for EC2 Fast Launch to require IAM policy attachment and auto-create CloudFormation resources. Added details about VPC, subnets, IMDSv2-enforced launch template, and restrictive security group.

Security assessment

The change enforces IMDSv2 (security hardening against SSRF vulnerabilities) and creates a security group with no rules (restrictive by default). The requirement to attach EC2FastLaunchFullAccess IAM policy ensures proper permissions. These are explicit security controls.

Diff

diff --git a/AWSEC2/latest/UserGuide/win-start-fast-launch-prereqs.md b/AWSEC2/latest/UserGuide/win-start-fast-launch-prereqs.md
index 0dbf1a6ba..16976b7ee 100644
--- a//AWSEC2/latest/UserGuide/win-start-fast-launch-prereqs.md
+++ b//AWSEC2/latest/UserGuide/win-start-fast-launch-prereqs.md
@@ -9 +9 @@ Before you set up EC2 Fast Launch, verify that you've met the following prerequi
-  * If you don't use a launch template to configure your settings, ensure that a default VPC is configured for the Region in which you use EC2 Fast Launch.
+  * If you provide a custom launch template when you configure EC2 Fast Launch, the service uses the VPC and other configuration settings that you've defined in the launch template. For more information, see [Use a launch template when you set up EC2 Fast Launch](./win-fast-launch-configure.html#win-fast-launch-with-template).
@@ -11 +11 @@ Before you set up EC2 Fast Launch, verify that you've met the following prerequi
-If you accidentally delete your default VPC in the Region where you plan to configure EC2 Fast Launch, you can create a new default VPC in that Region. To learn more, see [Create a default VPC](https://docs.aws.amazon.com/vpc/latest/userguide/default-vpc.html#create-default-vpc) in the _Amazon VPC User Guide_.
+  * If you don't use a custom launch template to configure your settings, you must attach the [EC2FastLaunchFullAccess](./security-iam-awsmanpol.html#security-iam-awsmanpol-EC2FastLaunchFullAccess) policy to your current IAM role before you enable EC2 Fast Launch. Then the service automatically creates an AWS CloudFormation stack with the following resources in your AWS account.
@@ -13 +13 @@ If you accidentally delete your default VPC in the Region where you plan to conf
-  * To specify a non-default VPC, you must use a launch template when you configure Windows fast launch. For more information, see [Use a launch template when you set up EC2 Fast Launch](./win-fast-launch-configure.html#win-fast-launch-with-template).
+    * A virtual private cloud (VPC)
@@ -15 +15,5 @@ If you accidentally delete your default VPC in the Region where you plan to conf
-  * If your account includes a policy that enforces IMDSv2 for Amazon EC2 instances, you must create a launch template that specifies the metadata configuration to enforce IMDSv2.
+    * Private subnets across multiple Availability Zones
+
+    * A launch template configured with Instance Metadata Service Version 2 (IMDSv2)
+
+    * A security group with no inbound or outbound rules