CVE Vulnerabilities

CVE-2021-37690

Use After Free

Published: Aug 13, 2021 | Modified: Nov 21, 2024
CVSS 3.x
6.6
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
CVSS 2.x
4.6 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

TensorFlow is an end-to-end open source platform for machine learning. In affected versions when running shape functions, some functions (such as MutableHashTableShape) produce extra output information in the form of a ShapeAndType struct. The shapes embedded in this struct are owned by an inference context that is cleaned up almost immediately; if the upstream code attempts to access this shape information, it can trigger a segfault. ShapeRefiner is mitigating this for normal output shapes by cloning them (and thus putting the newly created shape under ownership of an inference context that will not die), but we were not doing the same for shapes and types. This commit fixes that by doing similar logic on output shapes and types. We have patched the issue in GitHub commit ee119d4a498979525046fba1c3dd3f13a039fbb1. 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.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Name Vendor Start Version End Version
Tensorflow Google 2.3.0 (including) 2.3.4 (excluding)
Tensorflow Google 2.4.0 (including) 2.4.3 (excluding)
Tensorflow Google 2.5.0 (including) 2.5.0 (including)
Tensorflow Google 2.6.0-rc0 (including) 2.6.0-rc0 (including)
Tensorflow Google 2.6.0-rc1 (including) 2.6.0-rc1 (including)
Tensorflow Google 2.6.0-rc2 (including) 2.6.0-rc2 (including)

Potential Mitigations

References