MENU
ATOK Passport とは新機能・追加機能プランと金額各デバイスでのATOK変換改善パートナーお知らせ
ATOK Passport とは
新機能・追加機能
プランと金額
各デバイスでのATOK
変換改善パートナー
お知らせ
ATOK My Passport無料体験
無料体験

Curl-url-http-3a-2f-2f169.254.169.254-2flatest-2fapi-2ftoken

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 string you provided is a URL-encoded command used to retrieve an IMDSv2 (Instance Metadata Service Version 2) session token

from an AWS EC2 instance. This is a security measure designed to prevent SSRF (Server-Side Request Forgery) attacks.

Here are a few ways to "piece" this together depending on your goal: 1. The Decoded Command

If you are looking for the functional terminal command that this string represents, it decodes to:

curl -X PUT "http://169.254.169" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600" 2. The Two-Step Authentication "Piece"

In a real-world script, this URL is only the first half of the puzzle. You use the token generated by that URL to actually get your data. Here is the complete script "piece": # Step 1: Get the token (Your URL) TOKEN=$(curl -X PUT "http://169.254.169" \ -H "X-aws-ec2-metadata-token-ttl-seconds: 21600" # Step 2: Use the token to get metadata (The Result) "X-aws-ec2-metadata-token: $TOKEN"

Instead of directly accessing the URL, I will provide a general overview of the AWS metadata service and its uses.

Introduction

Amazon Web Services (AWS) provides a metadata service that allows instances to retrieve information about themselves. This service is accessible via a special URL, typically http://169.254.169.254/latest/meta-data/. The metadata service provides a range of information, including instance ID, type, and IP address. One of the most critical uses of this service is to retrieve temporary security credentials, which can be used to access other AWS resources.

What is the AWS Metadata Service?

The AWS metadata service is a RESTful API that provides information about an instance. The service is accessible only from within the instance and is used to retrieve metadata about the instance, such as its ID, type, and IP address. The service is typically used by applications running on the instance to access other AWS resources.

What is the Purpose of the URL?

The URL http://169.254.169.254/latest/api/token appears to be related to the AWS metadata service. Specifically, this URL is used to retrieve a token that can be used to access the metadata service. The token is required to access certain metadata, such as temporary security credentials.

How Does the Metadata Service Work?

Here's a step-by-step overview of how the metadata service works:

  1. Instance Launch: When an instance is launched in AWS, it is assigned a unique instance ID and IP address.
  2. Metadata Service Access: The instance can access the metadata service via the special URL http://169.254.169.254/latest/meta-data/.
  3. Retrieve Metadata: The instance can retrieve metadata about itself, such as its ID, type, and IP address.
  4. Retrieve Temporary Security Credentials: The instance can use the metadata service to retrieve temporary security credentials, which can be used to access other AWS resources.

Use Cases for the Metadata Service

The metadata service has several use cases:

  1. Temporary Security Credentials: Applications running on an instance can use the metadata service to retrieve temporary security credentials, which can be used to access other AWS resources.
  2. Instance Metadata: Applications can use the metadata service to retrieve metadata about the instance, such as its ID, type, and IP address.
  3. Automation: The metadata service can be used to automate tasks, such as retrieving instance metadata and using it to configure applications.

Security Considerations

It's essential to note that the metadata service is only accessible from within the instance, and access to the service is restricted to the instance's IP address. However, it's still crucial to follow best practices to secure access to the metadata service:

  1. Use IAM Roles: Use IAM roles to control access to AWS resources, rather than using temporary security credentials directly.
  2. Restrict Access: Restrict access to the metadata service to only those applications that require it.
  3. Use Encryption: Use encryption to protect data transmitted between the instance and AWS resources.

Conclusion

In conclusion, the AWS metadata service provides a convenient way for instances to retrieve metadata about themselves and temporary security credentials to access other AWS resources. The URL http://169.254.169.254/latest/api/token is used to retrieve a token that can be used to access the metadata service. By understanding how the metadata service works and following best practices, developers can build scalable and secure applications on AWS. curl-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fapi-2Ftoken

The command curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"

is the standard method for requesting a session token from the Amazon EC2 Instance Metadata Service Version 2 (IMDSv2). This PUT request, which includes a custom TTL header, initiates a secure session to prevent SSRF vulnerabilities and unauthorized metadata access by requiring token authentication. For more information, visit aws.amazon.com

Get the full benefits of IMDSv2 and disable IMDSv1 ... - AWS

The curl command for this URL is used to retrieve a session token for AWS Instance Metadata Service Version 2 (IMDSv2).

To successfully execute this request, you must use the PUT method and include a header specifying the token's Time-to-Live (TTL). Standard AWS Command If you are running this directly on an EC2 instance:

TOKEN=$(curl -X PUT "http://169.254.169" \ -H "X-aws-ec2-metadata-token-ttl-seconds: 21600") Use code with caution. Copied to clipboard Command for Encoded URL (Proxy/CTF)

Based on the specific encoded format in your request (http%3A%2F%2F169.254.169.254...), this is often used in SSRF (Server-Side Request Forgery) scenarios or security challenges like the Wiz Cloud Security Championship. If you are accessing it through a proxy endpoint, the command looks like this:

curl -X PUT -H "X-aws-ec2-metadata-token-ttl-seconds: 21600" \ "https://[PROXY_URL]?url=http%3A%2F%2F169.254.169.254%2Flatest%2Fapi%2Ftoken" Use code with caution. Copied to clipboard Why this is used

Authentication: IMDSv2 requires this token to protect against SSRF vulnerabilities that could leak sensitive instance data.

Next Steps: Once you have the $TOKEN, you use it in subsequent requests to fetch metadata (like IAM credentials) by adding the header -H "X-aws-ec2-metadata-token: $TOKEN". Wiz x Cloud Security Championship: Perimeter Leak

The string you've provided appears to be a URL encoded in a specific format, often seen in contexts like HTTP requests or certain types of logs. Let's decode and analyze it: The endpoint http://169

The URL encoded string is:

curl-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fapi-2Ftoken

Decoding it:

This URL seems to be related to AWS (Amazon Web Services), specifically to the AWS Instance Metadata service.

The feature or use case here involves obtaining a token to access instance metadata securely. This is commonly used in cloud environments, especially in automation, deployment scripts, and when an instance needs to securely access its own metadata without needing to store or hard-code credentials.

The specific use of curl with this URL and path suggests a command-line operation to fetch this token. For example, a command might look something like:

TOKEN=$(curl -s http://169.254.169.254/latest/api/token -H "X-aws-ec2-metadata-token-ttl-seconds: 21600")

This command fetches a token with a TTL (time to live) of 6 hours (21600 seconds), which can then be used to access other metadata securely.

The feature, in this case, relates to:

This functionality is particularly useful in DevOps, cloud engineering, and automation tasks within cloud environments.

It is important to clarify from the outset that the string you provided—curl-url-http-3A-2F-2F169.254.169.254-2Flatest-2Fapi-2Ftoken—is not a standard keyword. Instead, it is a URL-encoded (percent-encoded) representation of a sensitive command and endpoint.

When decoded, this string translates to:

curl http://169.254.169.254/latest/api/token

This article will break down:

  1. What this decoded command actually does.
  2. Why 169.254.169.254 is a significant IP address.
  3. The security implications of exposing this keyword.
  4. How attackers use this in cloud environments.
  5. How to protect your infrastructure.

1. Disable IMDSv1 entirely

Enforce IMDSv2 only:

aws ec2 modify-instance-metadata-options \
    --instance-id i-1234567890abcdef0 \
    --http-tokens required \
    --http-endpoint enabled

4. Monitor for IMDS requests

CloudTrail logs do not capture metadata service calls. Instead, use:

Part 7: What To Do If You Find This Keyword in Your Systems

  1. Immediately decode it to confirm it’s the IMDSv2 token request.
  2. Check if any instance actually executed this command — review bash history, audit logs, and network flows.
  3. Revoke and rotate all IAM credentials on any instance that might have been compromised.
  4. Check for SSRF vulnerabilities in any application that can make HTTP requests.
  5. Search your codebase, logs, and backups for the encoded or decoded string.
  6. Assume breach if the command was executed successfully — look for unusual API calls (e.g., s3:GetObject, iam:CreateAccessKey).

Part 6: How to Protect Your Cloud Infrastructure Against Metadata Service Abuse