Quiet Riot

🎶 C'mon, Feel The Noise 🎶

An enumeration tool for scalable, unauthenticated validation of AWS principals; including AWS Acccount IDs, root e-mail addresses, users, and roles.

Credit: Daniel Grzelak @dagrz for identifying the technique and Will Bengston @__muscles for inspiring me to scale it.

See the introductory blog post here See a defender's perspective blog post here

Featureploitation Limits

Throttling

After performing extensive analysis of scaling methods using the AWS Python (Boto3) SDK, I was able to determine that the bottleneck for scanning (at least for Python and awscli -based tools) is I/O capacity of a single-threaded Python application. After modifying the program to run with multiple threads, I was able to trigger exceptions in individual threads due to throttling by the various AWS APIs. You can see the results from running a few benchmarking test scans here. APIs that I tested had wildly different throttling limits and notably, s3 bucket policy attempts took ~10x as long as similar attempts against other services.

With further testing, I settled on a combination of SNS, ECR-Public, and ECR-Private services running in US-East-1 in ~40%/50%/10% configuration split with ~700 threads. The machine I used was a 2020 Macbook Air (M1 and 16 GB RAM). This configuration yielded on average ~1100 calls/sec, though the actual number of calls can fluctuate significantly depending on a variety of factors including network connectivity. Under these configurations, I did occasionally throw an exception on a thread from throttling...but I have subsequently configured additional re-try attempts (4 -> 7) via botocore that will eliminate this issue with a minor performance trade-off.

Computational Difficulty

To attempt every possible Account ID in AWS (1,000,000,000,000) would require an infeasible amount of time given only one account. Even assuming absolute efficiency*, over the course of a day an attacker will only be able to make 95,040,000 validation checks. Over 30 days, this is 2,851,200,000 validation checks and we are still over 28 years away from enumerating every valid AWS Account ID. Fortunately, there is nothing stopping us from registering many AWS accounts and automating this scan. While there is an initial limit of 20 accounts per AWS organization, I was able to get this limit increased for my Organization via console self-service and approval from an AWS representative. The approval occured without any further questions and now I'm off to automating this writ large. Again, assuming absolute efficiency, the 28 years scanning could potentially be reduced down to ~100 days.

*~1100 API calls/check per second in perpetuity per account and never repeating a guessed Account ID.

Potential Supported Services

Getting Started With Quiet Riot

To get started with Quiet Riot, clone the repository to your local directory. You'll need boto3 and AWS cli tools installed. You'll need credentials configured with sufficient privileges in an AWS account to deploy the resources (SNS topic, ECR-Public repository, and ECR-Private repository). Then you just run ./main.py and follow the prompts.

If you want to footprint the services in-use (or previously in use) for a specific account, select footprint. It will automatically leverage a wordlist composed of service-linked roles that indicate a particular service is or has been in use in an account.

If you want to help identify valid Account IDs, you can select accounts and it will automatically generate a wordlist of random Account IDs of arbitrary (user-selected) size. Please consider making a pull request against the repository to include newly identified valid account IDs under wordlists/known_valid_account_ids.txt. I have collected <100k Account IDs and estimate there are between 50-60m Account IDs based on random sampling analysis.

Otherwise, you will want to use your own wordlist as a dictionary to guess User names or Role names for a specific account. If you don't bring your own wordlists, I recommend starting with SecLists Usernames.

Prerequisites

boto3/botocore
Sufficient AWS credentials configured via CLI