Denial of Service in Tensorflow

### Impact The `RaggedCountSparseOutput` does not validate that the input arguments form a valid ragged tensor. In particular, there is no validation that the `splits` tensor has the minimum required number of elements. Code uses this quantity to initialize a different data structure: https://github.com/tensorflow/tensorflow/blob/0e68f4d3295eb0281a517c3662f6698992b7b2cf/tensorflow/core/kernels/count_ops.cc#L241-L244 Since `BatchedMap` is equivalent to a vector, it needs to have at least one element to not be `nullptr`. If user passes a `splits` tensor that is empty or has exactly one element, we get a `SIGABRT` signal raised by the operating system. ### Patches We have patched the issue in 3cbb917b4714766030b28eba9fb41bb97ce9ee02 and will release a patch release. We recommend users to upgrade to TensorFlow 2.3.1. ### For more information Please consult [our security guide](https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md) for more information regarding the security model and how to contact us with issues and questions. ### Attribution This vulnerability is a variant of [GHSA-p5f8-gfw5-33w4](https://github.com/tensorflow/tensorflow/security/advisories/GHSA-p5f8-gfw5-33w4)

CVSS 3.1

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity from

GitHub (reviewed advisory)

Weakness

CWE-20

Also known as

BIT-tensorflow-2020-15199, CVE-2020-15199, PYSEC-2020-122, PYSEC-2020-279, PYSEC-2020-314

• github.com/tensorflow/tensorflow/security/advisories/GHSA-x5cp-9pcf-pp3h
• nvd.nist.gov/vuln/detail/CVE-2020-15199
• github.com/tensorflow/tensorflow/commit/3cbb917b4714766030b28eba9fb41bb97ce9ee02
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow-cpu/PYSEC-2020-279.yaml
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow-gpu/PYSEC-2020-314.yaml
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow/PYSEC-2020-122.yaml
• github.com/tensorflow/tensorflow
• github.com/tensorflow/tensorflow/releases/tag/v2.3.1