CVE-2020-15211

unknown
Published 2020-09-25 · Modified 2023-12-06
CVSS v3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS v2
VIR risk

Description

In TensorFlow Lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, saved models in the flatbuffer format use a double indexing scheme: a model has a set of subgraphs, each subgraph has a set of operators and each operator has a set of input/output tensors. The flatbuffer format uses indices for the tensors, indexing into an array of tensors that is owned by the subgraph. This results in a pattern of double array indexing when trying to get the data of each tensor. However, some operators can have some tensors be optional. To handle this scenario, the flatbuffer model uses a negative `-1` value as index for these tensors. This results in special casing during validation at model loading time. Unfortunately, this means that the `-1` index is a valid tensor index for any operator, including those that don't expect optional inputs and including for output tensors. Thus, this allows writing and reading from outside the bounds of heap allocated arrays, although only at a specific offset from the start of these arrays. This results in both read and write gadgets, albeit very limited in scope. The issue is patched in several commits (46d5b0852, 00302787b7, e11f5558, cd31fd0ce, 1970c21, and fff2c83), and is released in TensorFlow versions 1.15.4, 2.0.3, 2.1.2, 2.2.1, or 2.3.1. A potential workaround would be to add a custom `Verifier` to the model loading code to ensure that only operators which accept optional inputs use the `-1` special value and only for the tensors that they expect to be optional. Since this allow-list type approach is erro-prone, we advise upgrading to the patched code.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-15211

OS impact

OSVersionStatusFixed in
debian debianforkyfixed0
debian debiansidfixed0

Package impact

EcosystemPackageVulnerableFixed
python PyPItensorflow<1.15.41.15.4
python PyPItensorflow>=2.0.0,<2.0.32.0.3
python PyPItensorflow>=2.1.0,<2.1.22.1.2
python PyPItensorflow>=2.2.0,<2.2.12.2.1
python PyPItensorflow>=2.3.0,<2.3.12.3.1
python PyPItensorflow-cpu<1.15.41.15.4
python PyPItensorflow-cpu>=2.0.0,<2.0.32.0.3
python PyPItensorflow-cpu>=2.1.0,<2.1.22.1.2
python PyPItensorflow-cpu>=2.2.0,<2.2.12.2.1
python PyPItensorflow-cpu>=2.3.0,<2.3.12.3.1
python PyPItensorflow-gpu<1.15.41.15.4
python PyPItensorflow-gpu>=2.0.0,<2.0.32.0.3
python PyPItensorflow-gpu>=2.1.0,<2.1.22.1.2
python PyPItensorflow-gpu>=2.2.0,<2.2.12.2.1
python PyPItensorflow-gpu>=2.3.0,<2.3.12.3.1
python PyPItensorflow<1970c2158b1ffa416d159d03c3370b9a462aee35||>=2.3.0,<2.3.1e11f55585f614645b360563072ffeb5c3eeff162
python PyPItensorflow-gpu<1970c2158b1ffa416d159d03c3370b9a462aee35||>=2.3.0,<2.3.1e11f55585f614645b360563072ffeb5c3eeff162
python PyPItensorflow-cpu<1970c2158b1ffa416d159d03c3370b9a462aee35||>=2.3.0,<2.3.1e11f55585f614645b360563072ffeb5c3eeff162

References

Verify integrity in audit chain (admin only). AS-IS.