Request-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta Data-2fiam-2fsecurity Credentials-2f |top| Online

In the realm of cloud computing, particularly within Amazon Web Services (AWS), a specific request URL holds considerable importance for managing and accessing security credentials. The URL in question is http://169.254.169.254/latest/meta-data/iam/security-credentials/ . This address is not just a random string of characters but a gateway to a feature of AWS known as Instance Metadata Service.

AWS hosts the IMDS at this endpoint. It provides configuration data to managing applications, including network configurations, instance IDs, and—most importantly—associated Identity and Access Management (IAM) role credentials. 2. The Mechanics of an SSRF Attack

This URL is the textbook example of a Server-Side Request Forgery (SSRF) vulnerability within a cloud environment.

Theft. Up to this point, you may be assuming that, to get access to IMDS, you need to have a shell session on the cloud-based syst... Yusuf TEZCAN AWS EC2 Credentials Theft via SSRF Abuse - Hacking Articles In the realm of cloud computing, particularly within

In modern cloud computing, security vulnerabilities often arise not from traditional code bugs, but from architectural misunderstandings. One of the most famous and critical entry points for cloud exploitation centers around a specific IP address and URL path: http://169.254.169 .

Web servers log incoming traffic or application inputs using specific encodings to handle special characters. decodes to a colon ( : ). 2F decodes to a forward slash ( / ).

IMDSv2 adds and a required PUT header ( X-aws-ec2-metadata-token ). This blocks many SSRF attacks because simple GET requests are ignored. AWS hosts the IMDS at this endpoint

The process works as follows:

: The EC2 instance can then use these temporary credentials to access AWS resources securely.

AWS SDKs use this exact pathway automatically to sign API requests without requiring developers to hardcode keys into their software. The Security Threat: SSRF Vulnerabilities The Mechanics of an SSRF Attack This URL

: This part of the path specifically requests IAM (Identity and Access Management) security credentials. IAM is a service that allows you to manage access to AWS resources by creating user identities, roles, and policies. The security credentials provided through this endpoint are temporary and can be used by applications running on the EC2 instance to access AWS resources.

To an attacker, the IMDS endpoint is a goldmine. Here’s why:

The attacker configures their local AWS CLI with these stolen keys and begins scanning your S3 buckets or launching new instances. IMDSv1 vs. IMDSv2: The Essential Defense

Log all outgoing HTTP requests to 169.254.169.254 . Alert when unexpected processes (e.g., a web server UID) make such calls.

To fetch credentials under IMDSv2, a client must first execute a PUT request to generate a secret token, and then pass that token in an HTTP header during the subsequent GET request: