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

The IP address 169.254.169.254 is a special IPv4 address reserved for link-local communication. In cloud environments like AWS (and similarly in Google Cloud and Microsoft Azure with different paths), this address hosts the . It is only accessible from within the running cloud instance itself; it cannot be reached from the public internet. 3. The Path to IAM Credentials

: The AWS instance can query the metadata service at http://169.254.169.254 for information about itself and its environment.

We can leverage this to make a request to http://169.254.169.254 . * To determine if the EC2 instance has an IAM role associated w... Hacking The Cloud What is 169.254.169.254? - Kontra Hands-on Labs 5 Nov 2024 —

: Assign IAM roles with the least privilege necessary for the instance to perform its tasks.

However, if an application hosted on an EC2 instance is vulnerable to a Server-Side Request Forgery (SSRF) attack, this exact URI becomes the primary target for attackers seeking to hijack the instance's IAM role. The IP address 169

Breaking In: Fetching EC2 IAM Credentials. With SSRF confirmed, my next goal was to access the EC2 instance metadata service to lo... Mostafa Hussein Cloud Instance Metadata Services (IMDS) - LinkedIn

If you append the specific IAM role name to the end of that URL (e.g., .../security-credentials/my-ec2-role ), the service will return a JSON object containing: SecretAccessKey Token (Session Token) Expiration Date

A image-processing service that lets users provide a URL to fetch an image. The server blindly fetches the URL — and the attacker gives the metadata endpoint.

If a server-side script executes shell commands that include user input, an attacker might inject: * To determine if the EC2 instance has

A Server-Side Request Forgery (SSRF) vulnerability occurs when a web application fetches a remote resource without validating the user-supplied URL.

Configure network firewalls to block outbound traffic from the application layer to 169.254.169.254 .

http://169.254.169 provides temporary security credentials for AWS EC2 instances via the IAM role attached to the server. While useful for avoiding hardcoded credentials, this endpoint presents a significant Server-Side Request Forgery (SSRF) risk if not properly secured. To mitigate risks, it is crucial to adopt Instance Metadata Service Version 2 (IMDSv2), which requires a session token, and to follow the principle of least privilege for IAM roles. You can find more information about securing EC2 metadata on the AWS website.

To keep your cloud environment secure, follow these three steps: To mitigate risks

: Refers to the highest version of the metadata API supported by the instance.

: This is a link-local address used by cloud providers (AWS, GCP, Azure) to host metadata services. It is not routable over the internet, meaning it can only be reached from inside the cloud network.

: This path indicates that the request is for the latest version of metadata available. The /meta-data/ part specifies that the request is seeking metadata about the instance.