Ballot SC-080 V3: "Sunset the use of WHOIS to identify Domain Contacts and relying DCV Methods"

[ryancdickson]

[Note: This Pull Request will be used to facilitate a discussion period for Ballot SC-080 V3, planned to begin tomorrow (October 22, 2024)].

Purpose of Ballot SC-080 V3: This ballot proposes updates to the Baseline Requirements for the Issuance and Management of Publicly-Trusted TLS Server Certificates (TLS BRs) to address concerns regarding the use of WHOIS and HTTPS websites for identifying Domain Contacts.

Background: This ballot intends to accomplish two objectives, originally described in [1].

Objective 1: Enhance WHOIS/RDAP validation of gTLDs with comparable security properties to DNS-based validation.

Justification:

• A recent disclosure [2] demonstrated how threat actors could exploit deficiencies in the WHOIS protocol and WHOIS tools served via HTTPS websites to obtain fraudulent TLS certificates.
• Discussions within the Mozilla Dev Security Policy (MDSP) community [3] further expressed corresponding risks related to WHOIS, while also noting that ccTLDs may not maintain accurate or up-to-date WHOIS server records. Several examples of inoperative WHOIS servers for ccTLDs were identified.
• Solutions to strengthen existing WHOIS lookup methods were proposed in [5] and some are considered in this ballot.

Objective 2: Sunset Methods 3.2.2.4.2 (“Email, Fax, SMS, or Postal Mail to Domain Contact”) and 3.2.2.4.15 (“Phone Contact with Domain Contact”).

Justification:

• While solutions to strengthen WHOIS-relying DCV methods are considered in this ballot (see above), there is limited public evidence of significant reliance on these methods, including in response to [3] and [6].
• Instead, discussion has identified at least one CA Owner has already sunset reliance on WHOIS [7], and another that has changed its approach [8] for relying on WHOIS since disclosure of [2].
• More modern and heavily relied-upon DCV methods offer advantages over the existing WHOIS-based methods, including greater opportunity for seamless certificate lifecycle management automation (e.g., [9] and [10]), while also benefiting from recently improved security practices [11]. These methods can also more effectively align subscriber capabilities with agility and resilience expectations necessary to respond to the revocation timelines described in the TLS BRs [12].
• Beyond the above, previous discussions within the CA/Browser Forum have raised concerns about the perceived value (e.g., [13]) and security (e.g., [14]) of the DCV methods relying on WHOIS, further supporting the rationale for their gradual sunset.

Benefits of adoption:

• Enhanced Security: Eliminates reliance on outdated and vulnerable DCV methods that cannot consistently provide the security required by the TLS BRs, or benefit from recent DCV security enhancements (i.e., Multi-Perspective Issuance Corroboration [11]).
• Increased Agility: Encourages site owners to transition to modern DCV methods, creating opportunities for faster, more efficient, and less error-prone certificate lifecycle management.
• Opportunity for Innovation: Promotes the development of new and/or improved DCV methods, fostering innovation that may enhance the overall security and agility of the ecosystem.

Proposed Key Dates: The effective dates considered in this update are intended to 1) address the immediate concerns identified by [2], and 2) offer near-term and longer-term transition periods for subscribers and CA Owners relying on existing implementations of these methods.

January 15, 2025: For Methods 3.2.2.4.2, 3.2.2.4.12, and 3.2.2.4.15...

• CAs MUST NOT rely on Domain Contact information obtained using an HTTPS website, regardless of whether previously obtained information is within the allowed reuse period.
• When obtaining Domain Contact information for a requested Domain Name using the WHOIS protocol (RFC 3912) or the Registry Data Access Protocol (RFC 7482), the CA must follow specific practices (described in the ballot).
• CAs MUST NOT rely on cached 1) WHOIS server information that is more than 48 hours old, or 2) RDAP bootstrap data from IANA that is more than 48 hours old, to ensure that it relies upon up-to-date and accurate information.

July 15, 2025:

• CAs MUST NOT issue subscriber certificates relying on Methods 3.2.2.4.2 ("Email, Fax, SMS, or Postal Mail to Domain Contact") or 3.2.2.4.15 ("Phone Contact with Domain Contact").
• Prior validations using these methods and validation data gathered therein MUST NOT be used to issue new Subscriber Certificates.

Proposal Revision History:

• Pre-Ballot Version 1 [4]
• Version 1 Ballot and discussion [15]
• Version 2 Pre-Release [17] and discussion [18]
• Version 2 Ballot [19] and discussion [20]
• Version 3 Pre-Release [21]
• Version 3 (introduced by this Pull Request)

References:
[1] https://archive.cabforum.org/pipermail/servercert-wg/2024-September/004900.html
[2] https://labs.watchtowr.com/we-spent-20-to-achieve-rce-and-accidentally-became-the-admins-of-mobi/
[3] https://groups.google.com/a/mozilla.org/g/dev-security-policy/c/FuOi_uhQB6U/m/hKJOz3XzAAAJ
[4] https://groups.google.com/a/mozilla.org/g/dev-security-policy/c/mAl9XjieSkA/m/oDNWxtPwAQAJ
[5] https://archive.cabforum.org/pipermail/servercert-wg/2024-September/004839.html
[6] https://archive.cabforum.org/pipermail/servercert-wg/2024-September/004844.html
[7] https://aws.amazon.com/blogs/security/aws-certificate-manager-will-discontinue-whois-lookup-for-email-validated-certificates/
[8] https://bugzilla.mozilla.org/show_bug.cgi?id=1917896
[9] https://cabforum.org/working-groups/server/baseline-requirements/requirements/#32247-dns-change
[10] https://cabforum.org/working-groups/server/baseline-requirements/requirements/#322419-agreed-upon-change-to-website---acme
[11] https://cabforum.org/working-groups/server/baseline-requirements/requirements/#3229-multi-perspective-issuance-corroboration
[12] https://cabforum.org/working-groups/server/baseline-requirements/requirements/#491-circumstances-for-revocation
[13] https://archive.cabforum.org/pipermail/servercert-wg/2018-August/000113.html
[14] https://lists.cabforum.org/pipermail/validation/2024-July/001995.html
[15] https://archive.cabforum.org/pipermail/servercert-wg/2024-September/004825.html
[16] https://github.com/ryancdickson/staging/compare/356799f0dcfe11deb0a375a11233403236ab72c9..7a2ea7b33611bebf006a99a9a82729f183143eac
[17] https://github.com/ryancdickson/staging/compare/ba28d04894d69c8fac62850b9d0de5061658c7c5..7a2ea7b33611bebf006a99a9a82729f183143eac
[18] ryancdickson#9
[19] https://github.com/cabforum/servercert/compare/ba28d04894d69c8fac62850b9d0de5061658c7c5..7f2b54cfa5b89f41458a88211566ce508c464804
[20] https://groups.google.com/a/groups.cabforum.org/g/servercert-wg/c/AyTKMqwbCzc/m/MZ1CwW5nAQAJ
[21] https://groups.google.com/a/groups.cabforum.org/g/servercert-wg/c/AyTKMqwbCzc/m/hjUhnaJsAgAJ