Impact
To mimic Python's indexing with negative values, TFLite uses ResolveAxis to convert negative values to positive indices. However, the only check that the converted index is now valid is only present in debug builds:
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// Handle negative index. A positive index 'p_idx' can be represented as a |
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// negative index 'n_idx' as: n_idx = p_idx-num_dims |
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// eg: For num_dims=3, [0, 1, 2] is the same as [-3, -2, -1] */ |
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int current = axis[idx] < 0 ? (axis[idx] + num_dims) : axis[idx]; |
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TFLITE_DCHECK(current >= 0 && current < num_dims); |
If the DCHECK does not trigger, then code execution moves ahead with a negative index. This, in turn, results in accessing data out of bounds which results in segfaults and/or data corruption.
Patches
We have patched the issue in 2d88f47 and will release patch releases for all versions between 1.15 and 2.3.
We recommend users to upgrade to TensorFlow 1.15.4, 2.0.3, 2.1.2, 2.2.1, or 2.3.1.
For more information
Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.
Attribution
This vulnerability has been reported by members of the Aivul Team from Qihoo 360.
Impact
To mimic Python's indexing with negative values, TFLite uses
ResolveAxisto convert negative values to positive indices. However, the only check that the converted index is now valid is only present in debug builds:tensorflow/tensorflow/lite/kernels/internal/reference/reduce.h
Lines 68 to 72 in 0e68f4d
If the
DCHECKdoes not trigger, then code execution moves ahead with a negative index. This, in turn, results in accessing data out of bounds which results in segfaults and/or data corruption.Patches
We have patched the issue in 2d88f47 and will release patch releases for all versions between 1.15 and 2.3.
We recommend users to upgrade to TensorFlow 1.15.4, 2.0.3, 2.1.2, 2.2.1, or 2.3.1.
For more information
Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.
Attribution
This vulnerability has been reported by members of the Aivul Team from Qihoo 360.