Callback-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta Data-2fiam-2fsecurity Credentials-2f [extra Quality]

, which requires a session-oriented token to access metadata. This effectively neutralizes most SSRF attacks because the attacker cannot easily perform the required PUT request to get the token through a simple URL parameter. Input Validation/Allowlisting:

: This path is part of the Instance Metadata Service provided by AWS. The Instance Metadata Service allows instances to access information about themselves without the need for pre-configured information (like static IP addresses). The /latest part refers to the latest version of the metadata service.

To understand why this keyword is highly sensitive, we must look at how the AWS Instance Metadata Service operates. AWS Retrieving Security Credentials from Instance Metadata , which requires a session-oriented token to access metadata

: Access to 169.254.169.254 is restricted to EC2 instances within AWS. Attempting to access this IP from outside AWS will not work.

Keywords used in article: callback-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fmeta data-2Fiam-2Fsecurity credentials-2F , IMDSv2, SSRF, AWS metadata service, cloud security, IAM role exploitation. The Instance Metadata Service allows instances to access

Understanding and Securing the AWS Metadata Service: http://169.254.169.254/latest/meta-data/iam/security-credentials/

The attacker locates a parameter in a web application that expects a URL—such as a profile picture upload via URL, a webhook configuration, or a "callback URL" parameter used in OAuth flows. AWS Retrieving Security Credentials from Instance Metadata :

: