Callback-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta Data-2fiam-2fsecurity Credentials-2f !new! Guide

The most effective defense against SSRF-based credential theft is migrating to . IMDSv2 requires a PUT request to first obtain a session token, which then must be included as a header in subsequent GET requests. This stops most SSRF attacks, which typically only support simple GET requests. Enforce IMDSv2 by setting http_tokens = "required" in your instance metadata options and http_put_response_hop_limit = 1 to prevent forwarding.

While intended for legitimate automation and configuration management, this endpoint—specifically http://169.254.169.254/latest/meta-data/iam/security-credentials/ —is a prime target for attackers exploiting vulnerabilities. What is 169.254.169.254 ? The IP address

A real-world attack exploiting a callback URL for credentials typically unfolds in a precise chain: Enforce IMDSv2 by setting http_tokens = "required" in

: The URL-encoded schema identifier separating the protocol from the host.

Follow the principle of least privilege. The IP address A real-world attack exploiting a

aws ec2 modify-instance-metadata-options \ --instance-id i-1234567890abcdef0 \ --http-tokens required \ --http-endpoint enabled Use code with caution. 2. Implement Network Security

When using callback URLs, it's essential to follow best practices to ensure security and reliability: Enforce IMDSv2 by setting http_tokens = "required" in

This URL is used in the context of AWS EC2 instances to fetch temporary security credentials. Here's a helpful text explaining what this URL is used for and how it works: