CVE-2020-15207: In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, to mimic Python's indexing with negative value

TensorFlow Lite (a machine learning framework for mobile and embedded devices) had a bug in versions before 1.15.4, 2.0.3, 2.1.2, 2.2.1, and 2.3.1 where it failed to properly validate array indices (positions) after converting negative numbers to positive ones. This allowed the program to access memory outside its intended bounds, causing crashes or data corruption. The vulnerability only appeared in non-debug builds because the validation check was disabled in those versions.