filename = request.args.get('file') with open('/var/log/app/' + filename, 'r') as f: return f.read()
: Deleting critical cloud backups and locking infrastructure until a ransom is paid. How the Vulnerability Occurs
encoded_path = "-file-..-2F..-2F..-2F..-2Fhome-2F-2A-2F.aws-2Fcredentials"
: If the server is an EC2 instance, use Amazon EC2 Instance Metadata Service Version 2 (IMDSv2) , which requires a session token and is resistant to SSRF and LFI-based credential theft. -file-..-2F..-2F..-2F..-2Fhome-2F-2A-2F.aws-2Fcredentials
: Replace all instances of 2F with / .
Cloud infrastructure security relies heavily on Identity and Access Management (IAM) keys. If a web application runs on a server (like an EC2 instance) where a developer or administrator previously configured the AWS CLI, the .aws/credentials file will contain plaintext secrets:
Marcus didn’t think much of the log alert at first. Just another scanned path in the penetration test report: filename = request
Bad actors may launch unauthorized EC2 instances to mine cryptocurrency or host malicious command-and-control servers.
The payload wasn’t targeting the server’s file system. It was targeting developer workstations . The * wildcard—who even implements glob expansion in an API endpoint?
The * wildcard in the path wasn’t a programming error. It was a signature. Cloud infrastructure security relies heavily on Identity and
: Authenticate as the compromised user to the AWS environment.
Log and alert on repeated ../ patterns, access attempts to /etc/passwd , /.aws/credentials , or ~/.ssh/id_rsa . Use intrusion detection systems (IDS) to flag such requests.
ALLOWED_FILES = ['config.yaml', 'data.json'] if requested_file not in ALLOWED_FILES: raise SecurityError("Access denied")
The AWS keys belonged to a developer who had stored them on an EC2 instance used for testing. The keys had full administrator access. Within hours, the attacker: