I,Paul Vanderslice, certify that:

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| 1.     | I  have reviewed this report on Form 10-K, and all reports on Form 10-D required  to be filed in respect of the period covered by this report on Form 10-K, of CD  2017-CD3 Mortgage Trust (the “Exchange Act periodic reports”);                                                                                                                                                                                                                                                                                                                                    |
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| 2.     | Based  on my knowledge, the Exchange Act periodic reports, taken as a whole, do not  contain any untrue statement of a material fact or omit to state a material  fact necessary to make the statements made, in light of the circumstances  under which such statements were made, not misleading with respect to the  period covered by this report;                                                                                                                                                                                                                           |
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| 3.     | Based  on my knowledge, all of the distribution, servicing and other information required  to be provided under Form 10-D for the period covered by this report is  included in the Exchange Act periodic reports;                                                                                                                                                                                                                                                                                                                                                               |
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| 4.     | Based  on my knowledge and the servicer compliance statement(s) required in this  report under Item 1123 of Regulation AB, and except as disclosed in the  Exchange Act periodic reports, the servicers have fulfilled their obligations  under the servicing agreement(s) in all material respects; and                                                                                                                                                                                                                                                                         |
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| 5.     | All  of the reports on assessment of compliance with servicing criteria for  asset-backed securities and their related attestation reports on assessment  of compliance with servicing criteria for asset-backed securities required to  be included in this report in accordance with Item 1122 of Regulation AB and  Exchange Act Rules 13a-18 and 15d-18 have been included as an exhibit to this  report, except as otherwise disclosed in this report. Any material instances  of noncompliance described in such reports have been disclosed in this report  on Form 10-K. |
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Ingiving the certifications above, I have reasonably relied on informationprovided to me by the following unaffiliated parties: Midland Loan Services, aDivision of PNC Bank, National Association; Park Bridge Lender Services LLC;Wells Fargo Bank, National Association; KeyBank National Association; AEGON USARealty Advisors, LLC; Deutsche Bank Trust Company Americas; CWCapital AssetManagement LLC; Rialto Capital Advisors, LLC; Pentalpha Surveillance LLC;CoreLogic Commercial Real Estate Services, Inc.; and National Tax Search, LLC.

 

Dated:March 29, 2018

 

/s/Paul VanderslicePaul Vanderslice 

President,Citigroup Commercial Mortgage Securities Inc.

(seniorofficer in charge of securitization of the depositor)