Callback-url-http-3a-2f-2f169.254.169.254-2flatest-2fmeta Data-2fiam-2fsecurity Credentials-2f Jun 2026

The response contains JSON similar to:

The URL http://169.254.169.254/latest/meta-data/iam/security-credentials/ is a standardized, internal-only API endpoint for cloud instances.

Detail the to prevent credential abuse?

The threat model of this callback exploit heavily depends on whether your cloud infrastructure relies on or IMDSv2 . Access instance metadata for an EC2 instance

An SSRF attack occurs when an attacker forces an application to make an HTTP request to a resource that the application should not normally access. The response contains JSON similar to: The URL http://169

: This is a link-local address used by cloud providers for metadata services.

The danger lies in the simplicity of the URL. If an attacker finds a vulnerability—a bug where your application can be forced to make HTTP requests to a URL chosen by the attacker—they can point the application to http://169.254.169.254/latest/meta-data/iam/security-credentials/ . If successful, the attacker can:

The callback URL http://169.254.169.254/latest/meta-data/iam/security-credentials/ is more than a simple string—it is a potential skeleton key to your cloud infrastructure. It represents a fundamental tension between operational ease and security. While AWS has provided excellent tools like IMDSv2 and GuardDuty, the responsibility ultimately lies with developers and cloud architects to adopt a “never trust, always verify” mindset.

The use of the http://169.254.169.254/latest/meta-data/iam/security-credentials/ URL provides several benefits, including: Access instance metadata for an EC2 instance An

Similar patterns have been observed in countless penetration tests and bug bounty reports:

The IP address 169.254.169.254 is a used specifically by AWS to provide instance metadata to the machine itself. It is not accessible from the public internet. The Attack Vector: SSRF

curl http://169.254.169.254/latest/meta-data/iam/security-credentials/MyAppRole

Once you have the role name, you query it directly to get the credentials: curl http://169.254.169 If an attacker finds a vulnerability—a bug where

A special internal address accessible only from within an EC2 instance. /latest/meta-data/iam/security-credentials/ This directory lists the IAM roles attached to the server.

: Ensure application "callback" fields do not allow private or link-local IP ranges (like 169.254.x.x or 10.x.x.x ).

The callback URL has some limitations: