Data-2fiam-2fsecurity Credentials-2f [2021]: Request-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta

: The credentials provided through this service are temporary and are meant for use by the EC2 instance to access AWS resources. Proper handling and security practices are crucial to prevent misuse.

| Feature | IMDSv1 | IMDSv2 | |---------|--------|--------| | Authentication | None | Token-based | | HTTP method | GET only | PUT (for token) + GET | | SSRF mitigation | None | Hop limit + token required | | Recommended | No | Yes |

Ensure that the IAM roles attached to your compute instances possess only the bare minimum permissions required to perform their tasks. Even if an attacker successfully extracts security credentials using SSRF, their blast radius is severely limited if the compromised role lacks permission to read sensitive databases or modify cloud infrastructure. Deploy Web Application Firewalls (WAF)

SSRF occurs when an attacker can cause a web application to send a crafted request to an unexpected destination. The Attack Scenario : The credentials provided through this service are

: AWS now supports IMDS version 2, which requires a session-oriented request (a PUT request to get a token first). This effectively mitigates most SSRF attacks because attackers typically can only control the URL of a GET request.

Please confirm, and I’ll proceed with that.

Instead of providing a valid image URL, the attacker inputs http://169.254.169[role-name] . the damage can be contained.

The Instance Metadata Service (IMDS) endpoint, specifically the 169.254.169.254 path, acts as a critical vulnerability, allowing attackers to leverage Server-Side Request Forgery (SSRF) to steal temporary IAM security credentials. To mitigate this risk, security best practices demand enforcing IMDSv2, implementing strict IAM least-privilege roles, and utilizing network-level blocks. Read the full technical breakdown at Medium .

: The application on the EC2 instance makes a request to http://169.254.169.254/latest/meta-data/iam/security-credentials/ .

: The EC2 instance makes a request to the metadata service at the specified URL. The Instance Metadata Service (IMDS) endpoint

Securing this endpoint requires a multi-layered defense strategy focusing on updated protocols and strict permission management. 1. Enforce IMDSv2 (The Most Effective Defense)

When an attacker successfully crafts a request to this URL through a vulnerable web application, they are attempting to trick the server into fetching its own internal metadata and displaying it to the user. Why This is Critical

169.254.169.254 is a special reserved for metadata services. It is not reachable from the public internet — only from within the virtual network of the cloud provider or from the instance itself.

Note: This exact technique was famously used in the massive Capital One data breach of 2019, resulting in the theft of over 100 million customer records. How to Secure Your Infrastructure

Even if credentials are leaked, the damage can be contained.