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

The Metadata Gate: Understanding SSRF and the AWS 169.254.169.254 Endpoint Introduction

| Action | Why | |--------|-----| | | It would leak credentials if run on an EC2 instance. | | Block outbound requests to 169.254.169.254 | Prevent SSRF attacks at network level. | | Disable IMDSv1 | Enforce IMDSv2 (requires session token). | | Review any callback/ webhook feature | Ensure it doesn’t allow arbitrary URLs. | | Rotate IAM credentials if exposed | Assume compromise if the callback was triggered. | The Metadata Gate: Understanding SSRF and the AWS 169

indicates a malicious attempt to exploit a web application's callback mechanism. By passing the AWS internal metadata IP address as a callback, an attacker aims to trick the server into leaking sensitive IAM (Identity and Access Management) role credentials. 2. Technical Analysis Target IP (169.254.169.254): | | Review any callback/ webhook feature |

Security experts at Varonis and across the industry recommend migrating to to prevent this exact scenario. Unlike the original version, IMDSv2: By passing the AWS internal metadata IP address