Motivated by the LHCb's very recent observation of exotic X0(2900) in the B+ → D+D−K+ process, for which could be a good open-charm ud¯c¯s tetraquark candidate, we endeavor to investigate its possibility by means of QCD sum rules. In technique, four configurations of interpolating currents with JP = 0+ are studied for the ud¯c¯s tetraquark state. In the end, mass values are calculated to be ... GeV for the axial vector diquark-axial vector antidiquark configuration and ... GeV for the scalar diquark-scalar antidiquark configuration, both of which are consistent with the experimental data 2.866 ± 0.007 ± 0.002 GeV of X0(2900) in view of the uncertainty. These results support that X0(2900) could be a 0+ tetraquark state with open-charm flavor.