Tighten regex used for S3 200 errors (#3130)

Author: mullermp

gems/aws-sdk-s3/CHANGELOG.md

@@ -1,6 +1,8 @@
 Unreleased Changes
 ------------------
 
+* Issue - Tighten regex used to check for S3 200 errors.
+
 1.170.0 (2024-11-06)
 ------------------
 

gems/aws-sdk-s3/lib/aws-sdk-s3/plugins/http_200_errors.rb

@@ -71,9 +71,9 @@ def incomplete_xml_body?(xml, output)
 
           def check_for_error(context)
             xml = context.http_response.body_contents
-            if xml.match(/\?>\s*<Error>/)
-              error_code = xml.match(/<Code>(.+?)<\/Code>/)[1]
-              error_message = xml.match(/<Message>(.+?)<\/Message>/)[1]
+            if xml.match(/<\?xml\s[^>]*\?>\s*<Error>/)
+              error_code = xml.match(%r{<Code>(.+?)</Code>})[1]
+              error_message = xml.match(%r{<Message>(.+?)</Message>})[1]
               S3::Errors.error_class(error_code).new(context, error_message)
             elsif incomplete_xml_body?(xml, context.operation.output)
               Seahorse::Client::NetworkingError.new(