CVE-2021-29531: TensorFlow is an end-to-end open source platform for machine learning. An attacker can trigger a `CHECK` fail in PNG encoding by providing an empty input…

PriorityP420medium5.5CVSS 3.1

AVLACLPRLUINSUCNINAH

EPSS

0.19%

8.7th percentile

TensorFlow is an end-to-end open source platform for machine learning. An attacker can trigger a `CHECK` fail in PNG encoding by providing an empty input tensor as the pixel data. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/e312e0791ce486a80c9d23110841525c6f7c3289/tensorflow/core/kernels/image/encode_png_op.cc#L57-L60) only validates that the total number of pixels in the image does not overflow. Thus, an attacker can send an empty matrix for encoding. However, if the tensor is empty, then the associated buffer is `nullptr`. Hence, when calling `png::WriteImageToBuffer`(https://github.com/tensorflow/tensorflow/blob/e312e0791ce486a80c9d23110841525c6f7c3289/tensorflow/core/kernels/image/encode_png_op.cc#L79-L93), the first argument (i.e., `image.flat().data()`) is `NULL`. This then triggers the `CHECK_NOTNULL` in the first line of `png::WriteImageToBuffer`(https://github.com/tensorflow/tensorflow/blob/e312e0791ce486a80c9d23110841525c6f7c3289/tensorflow/core/lib/png/png_io.cc#L345-L349). Since `image` is null, this results in `abort` being called after printing the stacktrace. Effectively, this allows an attacker to mount a denial of service attack. The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3 and TensorFlow 2.1.4, as these are also affected and still in supported range.

Affected

14 ranges

Vendor	Product	Version range	Fixed in
debian	tensorflow	—	—
google	tensorflow	< 2.1.4	2.1.4
google	tensorflow	>= 2.2.0 < 2.2.3	2.2.3
google	tensorflow	>= 2.3.0 < 2.3.3	2.3.3
google	tensorflow	>= 2.4.0 < 2.4.2	2.4.2
intel	optimization_for_tensorflow	>= 0 < 26eb323554ffccd173e8a79a8c05c15b685ae4d1	26eb323554ffccd173e8a79a8c05c15b685ae4d1
intel	optimization_for_tensorflow	>= 0 < 2.1.4	2.1.4
intel	optimization_for_tensorflow	>= 2.2.0 < 2.2.3	2.2.3
intel	optimization_for_tensorflow	>= 2.3.0 < 2.3.3	2.3.3
intel	optimization_for_tensorflow	>= 2.4.0 < 2.4.2	2.4.2
tensorflow	tensorflow	< 2.1.4	2.1.4
tensorflow	tensorflow	—	—
tensorflow	tensorflow	—	—
tensorflow	tensorflow	—	—

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvdv2.02.1LOWAV:L/AC:L/Au:N/C:N/I:N/A:P

vendor_debian2.5LOW

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.