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Changes to EC2 Metadata Service

Praveen Sripati takes a look at changes to the AWS EC2 Instance Metadata Service following attacks against Capital One and dozens of other organizations:

Captial One Bank (1) and 30 different organizations were hacked around end of July, I have written a blog (1) around the same time on how to recreate the hack in your own AWS account and also a few mitigations around the same. Now, AWS has made a few changes to the AWS EC2 Instance Metadata Service (IMDS) around the same (12). AWS re:Invent 2019 session (1) around the same has also been planned on December 5th, 2019. Will update with the link once the recording of the session has been uploaded.

The old/existing approach is called IMDSv1 and the new one IMDSv2. Although IMDSv1 solves a few problems like not storing the access keys on the EC2, it bought its own headaches which lead to the hacks.

Click through to see what these problems were and how they led to IMDSv2.