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

This can expose unintended or restricted resources which only the vulnerable system should have access to, inadvertently allowing ... Introduction to the Instance Metadata Service 20 Dec 2020 —

Cure the underlying application flaw by validating all user-supplied URLs against a strict whitelist. Block any inputs containing: Literal IP addresses ( 169.254.169.254 , 127.0.0.1 ). Hexadecimal, octal, or URL-encoded variations of those IPs. DNS names that resolve to local loopback or private ranges. Apply the Principle of Least Privilege This can expose unintended or restricted resources which

aws ec2 modify-instance-metadata-options \ --instance-id i-... \ --http-endpoint disabled Hexadecimal, octal, or URL-encoded variations of those IPs

If a server-side script executes shell commands that include user input, an attacker might inject: \ --http-endpoint disabled If a server-side script executes

Server-Side Request Forgery (SSRF) occurs when a vulnerable web application takes a user-supplied URL, fails to validate or sanitize it, and forces the back-end server to make an HTTP request to that URL. Why Attackers Target 169.254.169.254

Understanding the Risks of http://169.254.169 In the world of AWS cloud security, few URIs are as critical—and potentially dangerous—as http://169.254.169 . This specific endpoint is part of the EC2 Instance Metadata Service (IMDS), a powerful feature that allows running instances to retrieve configuration data without needing hardcoded credentials.