https://github.com/macmod/stars
A multi-cloud DNS record scanner that aims to help cybersecurity/IT analysts identify dangling CNAME records in their cloud DNS services that could possibly lead to subdomain takeover scenarios.
https://github.com/macmod/stars
aws azure cloud cloudflare cybersecurity digitalocean dns domain-takeover gcp infosec pentesting python python3 scanner security security-research security-tools subdomain subdomain-takeover takeover
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A multi-cloud DNS record scanner that aims to help cybersecurity/IT analysts identify dangling CNAME records in their cloud DNS services that could possibly lead to subdomain takeover scenarios.
- Host: GitHub
- URL: https://github.com/macmod/stars
- Owner: Macmod
- License: mit
- Created: 2023-02-16T14:37:42.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2023-03-17T19:09:48.000Z (about 2 years ago)
- Last Synced: 2025-03-28T00:41:29.457Z (2 months ago)
- Topics: aws, azure, cloud, cloudflare, cybersecurity, digitalocean, dns, domain-takeover, gcp, infosec, pentesting, python, python3, scanner, security, security-research, security-tools, subdomain, subdomain-takeover, takeover
- Language: Python
- Homepage:
- Size: 198 KB
- Stars: 49
- Watchers: 4
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# STARS
 
⭐ **STARS** ⭐ is a multi-cloud DNS record scanner that aims to help cybersecurity/IT analysts identify dangling CNAME records in their cloud DNS services that could possibly lead to subdomain takeover scenarios.
This is a small tool that uses some of the takeover ideas from [can-i-take-over-xyz](https://github.com/EdOverflow/can-i-take-over-xyz/) for defensive purposes in cloud environments. For each CNAME domain registered in a cloud environment, the tool generates **takeover factors** (factors that could indicate a subdomain takeover scenario) and **mitigation factors** (factors that possibly mitigate that scenario). The factors identified by this tool **should not be taken as definitive proof** of a subdomain takeover scenario on a domain, but rather **that a domain should be reviewed**.
Subdomain takeovers are complex issues that often happen because of a lack of appropriate processes of management/review in DNS zones, which is a common issue in large corporations. This tool can be used to find possible takeover issues in cloud DNS environments which host multiple zones with large record sets.
📚 To learn more about subdomain takeovers:
- [OWASP Article - Test for Subdomain Takeover](https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/02-Configuration_and_Deployment_Management_Testing/10-Test_for_Subdomain_Takeover)
- [HackTricks Article - Domain/Subdomain Takeover](https://book.hacktricks.xyz/pentesting-web/domain-subdomain-takeover)
# Checks
Currently the tool performs the following checks:
## Takeover Factors
- **DNS_NXDOMAIN** - The target domain resolves as NXDOMAIN
- **WEB_NOTFOUND** - The target domain returns a 404
- **WEB_FINGERPRINT** - The page at the target domain contains patterns related to a decomissioned page (such as "isn't available" or "doesn't exist")
## Mitigation Factors
- **PRIVATE_ZONE** - The zone where the source domain is hosted is private
- **AZURE_VERIFICATION_TXT** - There is a TXT entry for an Azure verification code at `asuid.source_domain`
# Prerequisites
If scanning Azure, AWS or GCP records, the appropriate CLI from the cloud you intend to scan needs to be installed before running the tool:
- [Azure CLI](https://learn.microsoft.com/en-us/cli/azure/install-azure-cli)
- [AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html)
- [GCloud CLI](https://cloud.google.com/sdk/docs/install?hl=pt-br)
- DigitalOcean - no need for CLI
- CloudFlare - no need for CLI
After that, run the following command to install the Python dependencies before running the tool:
```python
$ pip install -r requirements.txt
```
# Usage
## AWS Route53
```bash
$ aws configure
(Authenticate with your AWS credentials)
$ python stars.py --aws
```
PS. The recommended way of authenticating to AWS is using [AWS IAM Identity Center](https://docs.aws.amazon.com/cli/latest/userguide/sso-using-profile.html) to authenticate using `aws sso login` instead of providing an access key with `aws configure`, but the legacy way is easier to use and more widespread. You can also use [IAM roles](https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-role.html) directly if you intend to run the tool from AWS services such as an EC2 attached to a role via an instance profile.
## Azure DNS
```bash
$ az login
(Authenticate with your Azure credentials)
$ python stars.py --azure --subscription
```
## Google DNS
```bash
$ gcloud init
$ gcloud auth application-default login
(Authenticate with your GCP credentials and select your project)
$ python stars.py --gcp
```
## DigitalOcean DNS
```bash
$ export DIGITALOCEAN_ACCESS_TOKEN=""
$ python stars.py --digitalocean
```
## CloudFlare DNS
```bash
$ export CLOUDFLARE_API_TOKEN=""
$ python stars.py --cloudflare
```
## File DNS
A CSV file can also be used as input for the scan, if your DNS provider is not yet supported and you have a CSV with your CNAME records. The CSV should have the following columns (without a header line):
```
ZoneName,IsPrivate,RecordType,RecordName,RecordValue
```
```python
$ python stars.py --file
```
## Optional flags
- `--all-cnames` - Run the checks for all CNAME records in the environment, not just the ones in-scope (those known for subdomain takeover risks).
- `--dump-records` - Just dump all the records without performing any analysis.
- `--no-banners` - Don't show banners, just the results.
- `--no-colors` - Disable colorized output.
- `--no-table` - Disable building results table (just show results line-by-line).
- `--output FILE` - Write results to FILE.
- `--google-dns` - Use Google DoH for NXDOMAIN checks (by default it uses your local DNS resolver).
- `--nameservers NS1,NS2` - Use custom nameservers for NXDOMAIN checks.
## Example
[](https://asciinema.org/a/xHaSFEYEwU1kB8PIKwEdxsj8a)
# Extending functionality
The `scanners` package can be used in a standalone manner by other modules by importing the scanner classes from it (e.g. `from scanners.awsdns import AWSDNSScanner`), instantiating them and running their `fetch_records` method. The `fetch_records` of each scanner class is a generator that yields a dictionary for each DNS record in the specified environment in each iteration. Example:
```python
from scanners.awsdns import AWSDNSScanner
scanner = AWSDNSScanner()
for record in scanner.fetch_records():
print(record)
"""
"record" is a dict in the format:
{
"ZoneName": "DNS name of the zone",
"Private": True or False indicating whether the zone is private or not,
"Type": "Type of the record",
"Name": "Name of the record",
"Value": "Value of the record",
...other environment-specific values...
}
"""
```
Other checks against individual cloud DNS records (not just CNAME records) can be implemented using these classes, but since this project is aimed at the specific issue of domain takeover it will be left as future work if anyone is interested in developing other use cases.
# Contributing
Contributions are welcome by [opening an issue](https://github.com/Macmod/STARS/issues/new) or by [submitting a pull request](https://github.com/Macmod/STARS/pulls). If you find any bugs please let me know - I don't have many test environments to validate every edge case.
# Todo
Some ideas of new features to add that weren't included originally but would be nice to have in the future:
- Option to return the details of the record sets in CSV format
- Improve efficiency by providing an option of doing requests / lookups in parallel
- Option to only dump specific record types
- Also dump more advanced attributes of DNS records and zones in the scanners (TTL, weight, priority, provider-specific attributes, etc)
- Implement a local DB with results from previous executions (maybe)
- Check previously-scanned zones for DNS Takeover (maybe)
- Taking screenshots with a headless browser (maybe)
- Verify whether a domain is public knowledge by scraping with passive tools like Sublist3r (maybe)
# Domains Scope
If you run the tool without the `--all-cnames` flag, it will only report results on CNAMEs pointing to domains in the following scope:
| Kind | Domain |
|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Azure Services | *.cloudapp.net
*.cloudapp.azure.com
*.azurewebsites.net
*.blob.core.windows.net
*.azure-api.net
*.azurehdinsight.net
*.azureedge.net
*.azurecontainer.io
*.database.windows.net
*.azuredatalakestore.net
*.search.windows.net
*.azurecr.io
*.redis.cache.windows.net
*.azurehdinsight.net
*.servicebus.windows.net
*.visualstudio.com
|
| AWS S3 Buckets | *.s3.amazonaws.com
*.s3-website.region.amazonaws.com
*.s3.region.amazonaws.com
*.s3.dualstack.region.amazonaws.com |
| Wordpress | *.wordpress.com |
| Agile CRM | cname.agilecrm.com |
| ReadTheDocs | readthedocs.io |
| Canny.IO | cname.canny.io |
| Shopify | *.myshopify.com |
| Airee.RU | cdn.airee.ru |
The idea here is to only run the checks against CNAMEs pointing to services that have been seen in subdomain takeover cases. Most of these domains were hand-picked from the vulnerable services documented at the [can-i-take-over-xyz](https://github.com/EdOverflow/can-i-take-over-xyz/) project. Feel free to add more domains that could be subject to subdomain takeover to the scope by opening an issue.
# License
The MIT License (MIT)
Copyright (c) 2023 Artur Henrique Marzano Gonzaga
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.