The Collaborative International Dictionary of English v.0.48:

Undiscriminating \Undiscriminating\
   See discriminating.

WordNet (r) 3.0 (2006):

undiscriminating
    adj 1: not discriminating [syn: undiscriminating,
           indiscriminating] [ant: discriminating]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "undiscriminating":
   apathetic, ataractic, blanket, blase, careless, casual,
   devil-may-care, disinterested, dispassionate, disregardful,
   easygoing, general, heedless, imprudent, inattentive, incurious,
   indiscreet, indiscriminate, indiscriminating, indiscriminative,
   inexcitable, insensitive, insouciant, lackadaisical, listless,
   mindless, negligent, nonchalant, nonjudgmental, perfunctory,
   pococurante, promiscuous, reckless, regardless, sweeping, tactless,
   turned-off, unanxious, unconcerned, uncritical, uncriticizing,
   undemanding, undifferentiating, undiscreet, undiscriminated,
   undiscriminative, undistinguishing, unexacting, unfastidious,
   uninterested, unmeticulous, unmindful, unparticular, unselective,
   unsolicitous, unsubtle, untactful, wholesale