id: elasticbeantalk-takeover info: name: ElasticBeanTalk Subdomain Takeover Detection author: philippedelteil,rotemreiss severity: high description: ElasticBeanTalk subdomain takeover detected. A subdomain takeover occurs when an attacker gains control over a subdomain of a target domain. Typically, this happens when the subdomain has a canonical name (CNAME) in the Domain Name System (DNS), but no host is providing content for it. reference: - https://github.com/EdOverflow/can-i-take-over-xyz/issues/147 - https://twitter.com/payloadartist/status/1362035009863880711 - https://www.youtube.com/watch?v=srKIqhj_ki8 classification: cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N cvss-score: 7.2 cwe-id: CWE-404 metadata: comments: | Only CNAMEs with region specification are hijackable. You need to claim the CNAME in AWS portal (https://aws.amazon.com/) or via AWS CLI to confirm the takeover. Do not report this without claiming the CNAME. CLI command to verify the availability of the environment: aws elasticbeanstalk check-dns-availability --region {AWS_REGION} --cname-prefix {CNAME_PREFIX} For example: CNAME - 2rs3c.eu-west-1.elasticbeanstalk.com Command - aws elasticbeanstalk check-dns-availability --region eu-west-1 --cname-prefix 2rs3c tags: dns,takeover,aws dns: - name: "{{FQDN}}" type: A matchers-condition: and matchers: - type: regex regex: - \.(us|af|ap|ca|eu|me|sa)\-(east|west|south|northeast|southeast|central)\-[1-9]+\.elasticbeanstalk\.com - type: word words: - "NXDOMAIN" extractors: - type: regex group: 1 regex: - "IN\tCNAME\t(.+)" # Enhanced by mp on 2022/03/14