The endpoint http://169.254.169.254/latest/api/token is used to retrieve a session-based authentication token for the Amazon EC2 Instance Metadata Service Version 2 (IMDSv2), which mitigates SSRF vulnerabilities. It requires an HTTP PUT request to generate a token, which is then used to securely access instance-specific metadata. For more details, visit AWS Security Blog.
Get the full benefits of IMDSv2 and disable IMDSv1 ... - AWS
The keyword curl-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fapi-2Ftoken refers to the curl command used to retrieve a session token from the Amazon Web Services (AWS) Instance Metadata Service Version 2 (IMDSv2).
This specific URL (http://169.254.169.254/latest/api/token) is the gateway for a more secure way of accessing instance metadata—the data about your virtual machine, like its ID, public IP, and even temporary security credentials. Understanding the Command Breakdown
The keyword includes an encoded URL. Decoded, it reads: curl http://169.254.169.254/latest/api/token.
169.254.169.254: This is a link-local IP address. It is a special, non-routable address used by cloud providers (like AWS and Google Cloud) to provide information to a virtual machine about itself. curl-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fapi-2Ftoken
/latest/api/token: This is the specific endpoint in IMDSv2 used to request a session token.
curl -X PUT: To get the token, you must use a PUT request, which is a key security upgrade from the older version (IMDSv1) that only required simple GET requests. Why Is This Command Important? Medium·Gerald Nguyen
I notice you've shared what appears to be a URL encoded string that decodes to:
curl http://169.254.169.254/latest/api/token
This is a request to the AWS EC2 instance metadata service (IMDSv2), which uses the IP address 169.254.169.254 — a link-local address reserved for instance metadata. The endpoint http://169
If you're asking for a long write-up about this curl command, how it works, its security implications, and how it's used in cloud environments, I can provide that. However, I want to be clear that I won't assist with writing exploit code, attack methodologies, or any unauthorized access techniques.
Here is an educational and defensive write-up for cloud security professionals:
The specific notation provided in the prompt—curl-url-http-3A-2F-2F...—highlights how these endpoints are often represented in logs, documentation, or attack payloads.
http-3A-2F-2F translates to http://. In security logs, such as AWS CloudTrail or Web Application Firewall (WAF) logs, URLs are often stored in an encoded format.PUT request containing latest/api/token originating from an unexpected process (outside of standard SDKs or curl) may indicate a compromised instance or an active SSRF attack.The primary motivation for IMDSv2 was the mitigation of Server-Side Request Forgery (SSRF).
The IMDSv1 Vulnerability:
In v1, a vulnerable web application could be tricked into visiting http://169.254.169.254/latest/meta-data/iam/security-credentials/. The metadata service would return sensitive credentials in the HTTP response body, which the attacker could then capture. etc.)
Public GitHub repositories
The IMDSv2 Defense:
The IMDSv2 token endpoint requires the HTTP method PUT. This is a critical security feature. Most SSRF vulnerabilities in web applications exploit GET requests (e.g., fetching a URL provided by a user).
GET, it cannot retrieve a token from the PUT-only token endpoint.PUT, the response from the token endpoint contains only the token string, not the sensitive data itself.PUT request to get the token, extract that token, and then make a second GET request to the metadata endpoint injecting the token as a header.This multi-step complexity significantly raises the bar for exploitation, effectively neutralizing simple SSRF vectors.
If this string appears in:
…then an attacker who finds it can reconstruct the command and attempt to run it against any target server they control — or worse, if they have network access to your cloud environment, they can run it against your instance metadata service.
You could request:
curl http://169.254.169.254/latest/meta-data/iam/security-credentials/some-role
And it would directly return IAM credentials in plaintext. No authentication, no token, no headers. Any process on the VM — including a compromised web application — could get admin keys.