Once upon a time in the vast cloud of Amazon Web Services (AWS) , there lived a humble EC2 instance i-0abc12345
If you are a security researcher and you see curl http://169.254.169.254/latest/api/token in a target application, — especially on a production system. A single successful request could retrieve live IAM keys, which might be considered a violation of the bug bounty terms (or even computer fraud laws in some jurisdictions). curl-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fapi-2Ftoken
Since then, AWS introduced IMDSv2 (which requires a PUT token first). However, many legacy applications still use IMDSv1, or they misconfigure IMDSv2. Once upon a time in the vast cloud
169.254.169.254latest/meta-datalatest/api/token169.254.169.254 (decimal), 0xA9.0xFE.0xA9.0xFE, or hex encoding.