Quran confirms the True statements mentioned in the Old and New Testaments, but since many parts of the Old and New testaments were been distorted by people, the real testaments are not what is been claimed.
Quran does not confirm every thing which is been claimed by People of Book but it definitely confirms the Real facts in the original Testaments. This confirmation is mentioned in many Suras like:
al-Baqara 41, 91, 97,
Aal Imraan 3,
al-Ma'ida 46, 48