CVE-2020-26267: TensorFlow - Unvalidated DataFormatVecPermute API

Background

TensorFlow is an open-source machine learning framework developed by Google. It provides a comprehensive ecosystem of tools, libraries, and community resources for building and deploying machine learning models. The tf.raw_ops.DataFormatVecPermute API is a function in TensorFlow that allows users to permute the data format of tensors. This API is used to manipulate the order of dimensions in a tensor, typically used for data preprocessing or model optimization. However, in certain versions of TensorFlow, the src_format and dst_format attributes of this API are not properly validated, leading to potential security vulnerabilities.

Vulnerability Detail

The vulnerability in TensorFlow's tf.raw_ops.DataFormatVecPermute API arises from the lack of validation for the src_format and dst_format attributes. The code assumes that these two arguments define a permutation of NHWC (representing the dimensions of a tensor: batch size, height, width, and channels). However, due to the absence of proper validation, it is possible to provide invalid or malicious values for these attributes. This can result in uninitialized memory accesses, reading outside of bounds, and even crashes. An attacker could exploit this vulnerability to execute arbitrary code, leak sensitive information, or cause denial-of-service attacks.

Workaround

As a temporary workaround, users can avoid using the tf.raw_ops.DataFormatVecPermute API or ensure that the src_format and dst_format attributes are properly validated before calling the function. This can be done by implementing custom validation logic or using helper functions provided by the TensorFlow community. Here is an example of how to validate the attributes before calling the API:

import tensorflow as tf

def permute_data_format(src_format, dst_format):
    valid_formats = ['NHWC', 'NCHW', 'HWCN', 'CHWN']
    if src_format not in valid_formats or dst_format not in valid_formats:
        raise ValueError('Invalid data format')
    tf.raw_ops.DataFormatVecPermute(src_format=src_format, dst_format=dst_format)

Conclusion

In conclusion, the vulnerability in TensorFlow's tf.raw_ops.DataFormatVecPermute API can lead to serious security issues if not addressed. It is crucial to update TensorFlow to one of the fixed versions and follow the recommended upgrade instructions. Additionally, users can implement the provided workaround or custom validation logic to mitigate the risk. For further support on vulnerability remediation, contact DevNack.com.

See every vulnerability recorded for tensorflow →

FAQ