A safety investigator discovered that a Starbucks subdomain has a DNS pointer on an deserted Azure cloud host. The issue is that anyone who registers the cloud host would obtain the subdomain information.
Active CNAME blame record
The mistake involved leaving the CNAME (canonical name) document active on the subdomain “datacafe-cert.starbucks.com” pointing to an abandoned Azure resource called “s00397nasv101-datacafe-ert.azurewebsites.net.” If the Azure resource name is claimed, the Starbucks subdomain might be used to perform cross-site scripting (XSS) and session hijacking assaults, since it would have no impact with the same-origin policies (SOP). Acceptance of information from a lawful subdomain is a precious asset that can also be used for phishing attacks or malware distribution. Electronic Arts produced the same error a while ago, which was released by the safety professionals at the checkpoint in late June. This kind of safety problem often arises following a marketing campaign by a business that forgets to wash the DNS records once they have finished. It can also take place before the manufacturing phase when testing stuff.
Minimum effort to achieve maximum effect
On August 1, Parzel, a Berlin-based hacker, found the problem and reported to Starbucks via its HackerOne platform bug bounty program. The company paid a $2,000 reward for the private disclosure of the supervision. Parzel found the issue with the listing of different subdomains for the starbucks.com domain and looked for those with a CNAME record mapped to an Azure host. The investigator describes the following steps in the takeover process: “For every domain that matched I performed a DNS query for the CNAME record entry. If this returns a NXDOMAIN, the subdomain can usually be taken over and it is possible to register a domain that matches the NXDOMAIN CNAME entry.” Parzel recorded a service on Azure using the name of the subdomain Starbucks to avoid malicious use. A few days after the personal document, Parzel noticed that the CNAME record had been deleted and the Azure name published. The subdomain of Starbucks is no longer present. This seems to be a recurrent problem with Starbucks because, a little over a year ago, a scientist who reported the same sort of issue with a different subdomain paid another $2,000. This report was also made by HackerOne. Credit: Bleeping computers
