Callback-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta Data-2fiam-2fsecurity Credentials-2f Jun 2026

: Applications running on the EC2 instance can then use these temporary credentials to make secure requests to AWS services.

In the world of cloud computing, convenience often walks hand-in-hand with risk. One of the most powerful—and infamous—examples of this duality is the link-local address 169.254.169.254 . To the uninitiated, the encoded string callback-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fmeta data-2Fiam-2Fsecurity credentials-2F might look like garbled text. However, to cloud security engineers and penetration testers, this URL (URL-encoded for safe transmission) represents a in many cloud architectures. : Applications running on the EC2 instance can

Using these credentials, the attacker may be able to access S3 buckets, databases, or other AWS services depending on the permissions of the IAM role. : Standard SSRF attacks usually only allow GET

: Standard SSRF attacks usually only allow GET requests, making it nearly impossible for an attacker to retrieve credentials if IMDSv2 is enforced. To the uninitiated

In the original version (IMDSv1), the request was a simple HTTP GET request (as described above). IMDSv2 adds a mandatory session layer:

To "prepare a post" regarding this specific callback URL string, it is important to recognize that this is a classic signature for a attack targeting the AWS Instance Metadata Service (IMDS) .