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AWS dms high security documentation change

Service: dms · 2026-01-31 · Security-related high

File: dms/latest/userguide/CHAP_Target.S3.md

Summary

Clarified S3 bucket ownership validation logic and cross-account requirements for ExpectedBucketOwner setting

Security assessment

Explicitly addresses spoofing prevention through bucket ownership validation. Documents critical cross-account security requirement (failure without proper config). Evidence: Direct security terms ('prevent spoofing', ownership validation) and failure scenario for cross-account access.

Diff

diff --git a/dms/latest/userguide/CHAP_Target.S3.md b/dms/latest/userguide/CHAP_Target.S3.md
index 364abe71e..6f2b29592 100644
--- a//dms/latest/userguide/CHAP_Target.S3.md
+++ b//dms/latest/userguide/CHAP_Target.S3.md
@@ -28 +28 @@ You can specify the column delimiter, row delimiter, and other parameters using
-You can specify a bucket owner and prevent sniping by using the `ExpectedBucketOwner` Amazon S3 endpoint setting, as shown following. Then, when you make a request to test a connection or perform a migration, S3 checks the account ID of the bucket owner against the specified parameter.
+To prevent spoofing, AWS DMS validates bucket ownership before performing operations. By default, when the `ExpectedBucketOwner` Amazon S3 endpoint setting is not specified, AWS DMS uses the AWS account ID that owns the AWS DMS service role as the expected bucket owner.
@@ -29,0 +30 @@ You can specify a bucket owner and prevent sniping by using the `ExpectedBucketO
+To migrate data to an S3 bucket owned by a different AWS account, you must explicitly specify the actual bucket owner in the `ExpectedBucketOwner` Amazon S3 endpoint setting, as shown following. Otherwise, the cross-account replication task will fail.
@@ -31 +32,2 @@ You can specify a bucket owner and prevent sniping by using the `ExpectedBucketO
-    --s3-settings='{"ExpectedBucketOwner": "_AWS_Account_ID_ "}'
+    
+    --s3-settings '{"ExpectedBucketOwner": "_AWS_Account_ID_ "}'