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: The default directory for AWS CLI configuration on Linux systems when running as the root user.

This attack occurs when an application includes a file without properly validating the input path.

In a vulnerable PHP application, the code might look something like this:

?>

The target file, /root/.aws/credentials , is a critical configuration file used by the AWS Command Line Interface (CLI) and SDKs. : The default directory for AWS CLI configuration

You might wonder: why not simply request ../../../../root/.aws/credentials ? There are two main reasons:

: This is the filter being applied. It instructs PHP to read the file and encode its contents using Base64.

is a Local File Inclusion (LFI) attack designed to exfiltrate AWS credentials by using PHP stream filters to base64-encode sensitive files [1]. This attack enables unauthorized access to AWS Access Key IDs and Secret Access Keys, potentially leading to full cloud environment compromise, and should be mitigated by disabling allow_url_include

Exposing the root AWS credentials file usually results in a catastrophic compromise of the cloud environment: You might wonder: why not simply request

To understand how this attack functions, we must break down the URL-encoded payload into its component parts:

They can now download entire S3 buckets, launch EC2 instances, or delete critical resources.

: Because the payload transmits data via standard Base64 text, traditional Web Application Firewalls (WAFs) looking for explicit AWS key signatures inside the HTTP response body are frequently bypassed. 4. Remediation and Prevention Strategies

Never pass raw user input directly into file-inclusion functions like include() , require() , or file_get_contents() . Use a strict whitelist of allowed filenames instead. is a Local File Inclusion (LFI) attack designed

: Used to sign programmatic requests to AWS services.

Understanding php://filter for LFI: Analyzing the base64-encode Attack on AWS Credentials

Protecting against this type of attack requires a defense-in-depth approach.