-file-..-2f..-2f..-2f..-2fhome-2f-2a-2f.aws-2fcredentials 2021 Review

The string you've provided appears to represent a file path that's been URL-encoded. Let's break it down to understand what it represents:

-file-..-2F..-2F..-2F..-2Fhome-2F-2A-2F.aws-2Fcredentials

Here's the decoding process:

1. URL Decoding: The string contains 2F which is the URL-encoded representation of /, and - remains -. -file-..-2F..-2F..-2F..-2Fhome-2F-2A-2F.aws-2Fcredentials

2. Decoding 2F: Replace all instances of 2F with /.

The decoded string then becomes:

-file-../../../../home/*/.aws/credentials The string you've provided appears to represent a

Let's further simplify this:

• The * in the path is a wildcard character that can match any characters (or none) in a specific part of the path.

So, the path seems to be pointing to a .aws/credentials file in a home directory, but it uses a lot of parent directory navigation (../) and a wildcard (*).

The .aws/credentials file typically holds AWS credentials for accessing AWS services. This file is crucial for developers and AWS CLI users to authenticate and interact with AWS resources. URL Decoding : The string contains 2F which

The path suggests a rather indirect way of pointing to the .aws/credentials file, possibly to avoid hard-coding a direct path. However, using such a dynamically referenced path can lead to security vulnerabilities if not properly sanitized, especially if the string is interpreted or executed by a program.

Decoding -file-..-2F..-2F..-2F..-2Fhome-2F-2A-2F.aws-2Fcredentials: A Deep Dive into Path Traversal and AWS Credential Theft

Prevention

1. Never accept user input for filesystem paths — use indexes or allow lists.
2. Sanitize input strictly — reject any path containing .., /, *, ~, or encoded variants.
3. Use chroot jails or containerized apps to restrict filesystem access.
4. Store AWS credentials properly — use IAM roles for EC2/ECS/Lambda instead of credentials files on disk.
5. Scan for .aws/credentials in web roots — it should never be there.
6. Apply least privilege — the web server user should not have read access to other users’ home directories.

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Practical Decoding and Handling in Code

If you were to handle such a path in a programming language like Python, you might decode it and handle it like so:

import urllib.parse
encoded_path = "-file-..-2F..-2F..-2F..-2Fhome-2F-2A-2F.aws-2Fcredentials"
# URL Decode
decoded_path = urllib.parse.unquote(encoded_path.replace('-', ''))
# Then process the path
import os
actual_path = os.path.join('/', decoded_path)
# For security, ensure to normalize the path and check if it's within a safe directory
safe_path = os.path.normpath(actual_path)
if safe_path.startswith('/home/*/.aws/credentials') or safe_path.endswith('.aws/credentials'):
    print("Path allowed")
else:
    print("Access denied due to path traversal risk")

Detection

Monitor logs for:

• ..%2F, ..%252F (double encoding), ..-2F style patterns.
• Parameters containing /home/*/.aws/credentials or similar.
• Access attempts to non-public files.
• Unusual wildcard * in file paths.

Sample Splunk or SIEM query:

"file" AND (".." OR "%2F" OR "..%2F") AND ".aws/credentials"

Threat Assessment