Fetch-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta Data-2fiam-2fsecurity Credentials-2f 2021 Jun 2026

: This part of the URL refers to the metadata service endpoint. The metadata service provides information about the instance, such as its ID, type, and IP address.

# boto3 automatically fetches credentials from the metadata endpoint import boto3 s3 = boto3.client('s3') s3.list_buckets()

If your application never needs to call AWS APIs, you can disable the metadata service entirely:

Understanding SSRF and the AWS Instance Metadata Service The string fetch-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fmeta data-2Fiam-2Fsecurity credentials-2F represents a URL-encoded payload designed to exploit Server-Side Request Forgery (SSRF) vulnerabilities [1]. : This part of the URL refers to

Server-Side Request Forgery occurs when a web application accepts a user-supplied URL, fails to validate it, and forces the backend server to make an HTTP request to that URL.

A poorly written PHP script that includes files via user input (e.g., ?page=../../../../ etc.) can sometimes be manipulated to make HTTP wrappers fetch remote URLs if allow_url_include is enabled.

Get the full benefits of IMDSv2 and disable IMDSv1 ... - AWS Server-Side Request Forgery occurs when a web application

This URL and the associated metadata service are powerful features of AWS that help manage access to resources securely. Proper understanding and utilization of these features are crucial for maintaining a secure and efficient cloud environment.

The attacker configures their local command-line interface (CLI) using the stolen Access Key ID, Secret Access Key, and Token.

The address 169.254.169.254 is a . This is a special, non-routable IP address range ( ) that is not accessible from the public internet. - AWS This URL and the associated metadata

Once an attacker possesses these credentials, they can configure their local AWS CLI and access your cloud environment with the same permissions as the compromised EC2 instance. Technical Impact

: Use IMDSv2 , which requires a session token and blocks these simple "fetch" requests.

Never give an EC2 instance AdministratorAccess . Only grant the specific permissions the app needs (e.g., s3:PutObject for a specific bucket). 3. Use Network Protections