eNom Inter-Account Transfer Issue
Posted on 05 September 2017
the m group security advisory [2017090100]: Zero-confirmation inter-account transfers of .uk domains with eNom * Discovery date: 2017-05-02 * Publish date: 2017-09-01 (+122 days) * Product: https://www.enom.com/, the website for eNom Inc. and their APIs, all eNom resellers * Vulnerable: yes, as of publication date 2017-09-01 * Impact: critical * Homepage: https://www.enom.com * Errata by: the m group, Sydney office, <hi@m.pr> * Reported by: the m group * URL: https://m.pr/enom-advisory-20170901.html Vendor description ------------------ eNom is one of the world's largest domain registrars holding over 15 million domain names as well as offering a host of domain and hosting related services. eNom are also a large internet reseller, powering at least part of the domain name registration systems for many registrars including NameCheap. Website: https://www.enom.com eNom were recently acquired by Tucows. Vulnerability & description --------------------------- eNom allows zero-confirmation .uk domain transfers between reseller accounts. This bypasses all account security and usual domain transfer authorization. Combined with instant IPS tag changes at Nominet, the .uk regional registrar, .uk domains can be hijacked within minutes and placed into a state where only a manual access restoration procedure with Nominet can recover the domains. This vulnerability is accessible to and impacts anyone with an eNom account or anyone with an account with an eNom reseller which provides automated domain transfers. The vulnerability is within eNom's .uk transfer system and impacts .uk domains only. It does not impact second level .??.uk domains such as .co.uk and .org.uk. Steps to reproduce ------------------ 1. Open an account with eNom or with an eNom reseller with integrates with eNom over their APIs, for example NameCheap. 2. Identify a .uk domain managed by eNom. Any .uk domain with an IPS tag set to ENOM is vulnerable. 3. Issue an inbound transfer request from the reseller. 4. Within a few minutes the .uk domain will "successfully complete" transfer to your reseller account with no notice given to the original owner and no confirmation of any kind required. 5. (optional) Immediately transfer the domain elsewhere by changing the IPS tag and registrant email address making the domain extremely difficult if not impossible to recover without a manual intervention by Nominet. Testing ------- Confirmed with domain hijacking between NameCheap and eNom using test domains. The eNom platform and all eNom resellers are assumed to be vulnerable. Solution -------- This vulnerability is with a remote hosted platform there is no available local solution until eNom resolve the security issue. Work-around ----------- Transfer all .uk domains away from eNom. Any .uk domains with the IPS tag set to ENOM should be transferred away from eNom immediately. NOTE: during our own domain migrations away from eNom it was discovered that eNom to not update .uk contact details in certain instances in their own control panel. This can cause domains to appear to have valid registrant contact email addresses but they actually have incorrect details stored at Nominet. Domains which have their IPS tags changed to push them away from eNom can then be left in a permanently locked and useless state as authorisation emails sent to invalid registrant contact addresses can never be authorized. It is critical that registrant contact details be force-updated from eNom's control panel before you change the IPS tags even if the contact details look correct or you may be required to manually contact Nominet (and pay a fee) to restore your domain. You can verify your .uk registrant contact details directly with Nominet by opening a Nominet Online Services account for free. Vendor contact timeline ----------------------- Extensive, see the full summary for details. 2017-05-02 (initial report) 2017-05-02 to 2017-08-29 - Significant contact with multiple eNom representatives. 2017-09-01 (+122 days) - Errata made public.
