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

The address 169.254.0.0/16 is a link‑local range. It is , but it is accessible from within the same virtual network or host. EC2 instances are automatically configured to route this IP to the metadata service. For an attacker on the outside, the only way to reach it is by tricking the victim’s own server into making the request.

Once the attacker has these keys, they can use them from their own machine to access other AWS services (like S3 buckets or RDS databases) that the role has permissions for. How to Defend Your Infrastructure

The server, running inside an EC2 instance, will happily fetch the metadata service and return the list of IAM roles. From there, the attacker requests .../security-credentials/MyAppRole and receives live AWS keys.

Even with IMDSv2, additional layers of protection are wise. The address 169

And receive a JSON response like:

It provides the instance with information about itself, such as its architecture, network configurations, and—most critically—temporary security credentials. Breaking Down the Target Payload

: This specific path is where AWS stores the temporary security tokens for the instance's IAM role. For an attacker on the outside, the only

The attacker changes the URL to image=http://169.254.169.254/latest/meta-data/iam/security-credentials/ .

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

In modern cloud computing, security isn't just about firewalls; it’s about managing identity and access permissions, especially for virtual machines. A critical, yet frequently targeted, component of Amazon Web Services (AWS) EC2 instances is the , specifically the endpoint accessed via: From there, the attacker requests

The link http://169.254.169.254 is an IP address that serves as a special endpoint within AWS, known as the Instance Metadata Service. This service provides instances with a way to access information about themselves, including metadata that can be used for configuration, management, and security purposes. The metadata service is accessible from within the instance and offers various pieces of information that are essential for dynamic configuration and management.

In cloud security, few strings of characters are as infamous as the local link-back address: 169.254.169.254 . When combined with specific paths, this IP address becomes the keys to the kingdom for attackers looking to compromise Amazon Web Services (AWS) infrastructure.

Never allow web applications to blindly fetch URLs provided by end-users.