CVE-2021-37687
Heap OOB in TFLite's `Gather*` implementations
Description
TensorFlow is an end-to-end open source platform for machine learning. In affected versions TFLite's [`GatherNd` implementation](https://github.com/tensorflow/tensorflow/blob/149562d49faa709ea80df1d99fc41d005b81082a/tensorflow/lite/kernels/gather_nd.cc#L124) does not support negative indices but there are no checks for this situation. Hence, an attacker can read arbitrary data from the heap by carefully crafting a model with negative values in `indices`. Similar issue exists in [`Gather` implementation](https://github.com/tensorflow/tensorflow/blob/149562d49faa709ea80df1d99fc41d005b81082a/tensorflow/lite/kernels/gather.cc). We have patched the issue in GitHub commits bb6a0383ed553c286f87ca88c207f6774d5c4a8f and eb921122119a6b6e470ee98b89e65d721663179d. 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.
How to fix CVE-2021-37687
To remediate CVE-2021-37687, upgrade the affected package to a fixed version below.
- —upgrade to 2.3.4 or later
- —upgrade to 2.3.4 or later
- —upgrade to eb921122119a6b6e470ee98b89e65d721663179d or later
- —upgrade to eb921122119a6b6e470ee98b89e65d721663179d or later
- —upgrade to 2.3.4 or later
- —upgrade to eb921122119a6b6e470ee98b89e65d721663179d or later
- —upgrade to 2.3.4 or later
Is CVE-2021-37687 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (7)
- >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3, >= 2.5.0, < 2.5.1
- from 0, < 2.3.4
- from 0, < eb921122119a6b6e470ee98b89e65d721663179d, < bb6a0383ed553c286f87ca88c207f6774d5c4a8f | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
- from 0, < eb921122119a6b6e470ee98b89e65d721663179d, < bb6a0383ed553c286f87ca88c207f6774d5c4a8f | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
- from 0, < 2.3.4
- from 0, < eb921122119a6b6e470ee98b89e65d721663179d, < bb6a0383ed553c286f87ca88c207f6774d5c4a8f | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
- from 0, < 2.3.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |