In the world of cloud computing, convenience often walks hand-in-hand with risk. One of the most powerful—and infamous—examples of this duality is the link-local address 169.254.169.254. To the uninitiated, the encoded string callback-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fmeta data-2Fiam-2Fsecurity credentials-2F might look like garbled text. However, to cloud security engineers and penetration testers, this URL (URL-encoded for safe transmission) represents a critical blind spot in many cloud architectures.
This article decodes that string, explains what it points to, why it is a high-value target for attackers, and how to secure it. In the world of cloud computing, convenience often
The URL provided is: http://169.254.169.254/latest/meta-data/iam/security-credentials/ This prevents most SSRF attacks because simple GET
AWS introduced IMDSv2, which requires a session-oriented PUT request to obtain a token before accessing metadata. This prevents most SSRF attacks because simple GET requests are ignored. explains what it points to
Enable IMDSv2 (with hop limit 1):
aws ec2 modify-instance-metadata-options \
--instance-id i-1234567890abcdef0 \
--http-tokens required \
--http-endpoint enabled \
--http-put-response-hop-limit 1