HIGH SEVERITYDNSID: fastly-cdn
Fastly CDN Dangling DNS Takeover Fingerprint
The CNAME points to Fastly edge routers, but no Fastly service is currently configured to handle requests for this host. Anyone with a Fastly account can claim the domain on their service.
CNAME Fingerprint Rule
*.fastly.net
404 / 500
Response Body Token
“Fastly error: unknown domain”
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 Fastly CNAME record from DNS or add the domain to your authorized Fastly service.
Immediate Defensive Checklist:
- Audit authoritative DNS zone records for any CNAME records pointing to
*.fastly.net. - 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 Fastly CDN In Real-Time
SubdomainWatch continuously monitors your DNS zones for orphaned Fastly CDN pointers, expired certificates, and dangling records 24/7.
Related Cloud Takeover Signatures
CLOUDCRITICAL
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*.s3.amazonaws.com / *.s3-website-*.amazonaws.com
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*.github.io
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Heroku App
*.herokudns.com / *.herokuapp.com
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Microsoft Azure App Service
*.azurewebsites.net / *.cloudapp.net
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AWS CloudFront
*.cloudfront.net
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AWS Elastic Beanstalk
*.elasticbeanstalk.com