CVE Vulnerabilities

CVE-2021-37652

Use After Free

Published: Aug 12, 2021 | Modified: Nov 21, 2024
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 the implementation for tf.raw_ops.BoostedTreesCreateEnsemble can result in a use after free error if an attacker supplies specially crafted arguments. The implementation uses a reference counted resource and decrements the refcount if the initialization fails, as it should. However, when the code was written, the resource was represented as a naked pointer but later refactoring has changed it to be a smart pointer. Thus, when the pointer leaves the scope, a subsequent free-ing of the resource occurs, but this fails to take into account that the refcount has already reached 0, thus the resource has been already freed. During this double-free process, members of the resource object are accessed for cleanup but they are invalid as the entire resource has been freed. We have patched the issue in GitHub commit 5ecec9c6fbdbc6be03295685190a45e7eee726ab. 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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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