PYSEC-2021-796

TensorFlow is an end-to-end open source platform for machine learning. In affected versions TFLite’s expand_dims.cc contains a vulnerability which allows reading one element outside of bounds of heap allocated data. If axis is a large negative value (e.g., -100000), then after the first if it would still be negative. The check following the if statement will pass and the for loop would read one element before the start of input_dims.data (when i = 0). We have patched the issue in GitHub commit d94ffe08a65400f898241c0374e9edc6fa8ed257. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.