CRITICAL SEVERITYHOSTINGID: heroku
Heroku App Dangling DNS Takeover Fingerprint
A DNS record points to a decommissioned Heroku dyno. An adversary can register a new Heroku application, attach your custom domain via the Heroku CLI, and immediately serve content under your authoritative domain.
CNAME Fingerprint Rule
*.herokudns.com / *.herokuapp.com
404 / 502
Response Body Token
“No such app”
When SubdomainWatch scanner receives HTTP responses matching this token on a dangling CNAME, it raises a critical alert immediately.
Remediation Guide & Mitigation
Action Required: Delete the dangling CNAME in DNS, or re-attach the domain to an active Heroku application inside your verified team account.
Immediate Defensive Checklist:
- Audit authoritative DNS zone records for any CNAME records pointing to
*.herokudns.com / *.herokuapp.com. - Verify whether the corresponding target resource is still active in your cloud tenant.
- If the service was deprecated, delete the DNS record immediately to prevent hijackers from claiming the endpoint.
- Add automated continuous monitoring to alert before third parties can register matching resource names.
Monitor Heroku App In Real-Time
SubdomainWatch continuously monitors your DNS zones for orphaned Heroku App pointers, expired certificates, and dangling records 24/7.
Related Cloud Takeover Signatures
CLOUDCRITICAL
AWS S3
*.s3.amazonaws.com / *.s3-website-*.amazonaws.com
HOSTINGCRITICAL
GitHub Pages
*.github.io
CLOUDCRITICAL
Microsoft Azure App Service
*.azurewebsites.net / *.cloudapp.net
CLOUDCRITICAL
AWS CloudFront
*.cloudfront.net
CLOUDCRITICAL
AWS Elastic Beanstalk
*.elasticbeanstalk.com
DNSHIGH
Fastly CDN
*.fastly.net