{"cve":"CVE-2021-29550","nvd":{"published":"2021-05-14T20:15:12.897","modified":"2026-06-17T03:47:53.483","status":"Modified","description":"TensorFlow is an end-to-end open source platform for machine learning. An attacker can cause a runtime division by zero error and denial of service in `tf.raw_ops.FractionalAvgPool`. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/acc8ee69f5f46f92a3f1f11230f49c6ac266f10c/tensorflow/core/kernels/fractional_avg_pool_op.cc#L85-L89) computes a divisor quantity by dividing two user controlled values. The user controls the values of `input_size[i]` and `pooling_ratio_[i]` (via the `value.shape()` and `pooling_ratio` arguments). If the value in `input_size[i]` is smaller than the `pooling_ratio_[i]`, then the floor operation results in `output_size[i]` being 0. The `DCHECK_GT` line is a no-op outside of debug mode, so in released versions of TF this does not trigger. Later, these computed values are used as arguments(https://github.com/tensorflow/tensorflow/blob/acc8ee69f5f46f92a3f1f11230f49c6ac266f10c/tensorflow/core/kernels/fractional_avg_pool_op.cc#L96-L99) to `GeneratePoolingSequence`(https://github.com/tensorflow/tensorflow/blob/acc8ee69f5f46f92a3f1f11230f49c6ac266f10c/tensorflow/core/kernels/fractional_pool_common.cc#L100-L108). There, the first computation is a division in a modulo operation. Since `output_length` can be 0, this results in runtime crashing. 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-369"],"references":["https://github.com/tensorflow/tensorflow/commit/548b5eaf23685d86f722233d8fbc21d0a4aecb96","https://github.com/tensorflow/tensorflow/security/advisories/GHSA-f78g-q7r4-9wcv","https://github.com/tensorflow/tensorflow/commit/548b5eaf23685d86f722233d8fbc21d0a4aecb96","https://github.com/tensorflow/tensorflow/security/advisories/GHSA-f78g-q7r4-9wcv"],"products":["google:tensorflow"],"source":"nvd","synced_at":"2026-10-19T21:18:09.669877188+00:00"},"epss":{"cve":"CVE-2021-29550","score":0.00189,"percentile":0.08573,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-f78g-q7r4-9wcv","url":"https://osv.dev/vulnerability/GHSA-f78g-q7r4-9wcv","summary":"Division by 0 in `FractionalAvgPool`","modified":"2026-07-08T06:28:55.334053984Z","packages":[{"ecosystem":"PyPI","name":"tensorflow","purl":"pkg:pypi/tensorflow","ranges":["<2.1.4"],"fixed":["2.1.4"]},{"ecosystem":"PyPI","name":"tensorflow","purl":"pkg:pypi/tensorflow","ranges":[">=2.2.0 <2.2.3"],"fixed":["2.2.3"]},{"ecosystem":"PyPI","name":"tensorflow","purl":"pkg:pypi/tensorflow","ranges":[">=2.3.0 <2.3.3"],"fixed":["2.3.3"]},{"ecosystem":"PyPI","name":"tensorflow","purl":"pkg:pypi/tensorflow","ranges":[">=2.4.0 <2.4.2"],"fixed":["2.4.2"]},{"ecosystem":"PyPI","name":"tensorflow-cpu","purl":"pkg:pypi/tensorflow-cpu","ranges":["<2.1.4"],"fixed":["2.1.4"]},{"ecosystem":"PyPI","name":"tensorflow-cpu","purl":"pkg:pypi/tensorflow-cpu","ranges":[">=2.2.0 <2.2.3"],"fixed":["2.2.3"]},{"ecosystem":"PyPI","name":"tensorflow-cpu","purl":"pkg:pypi/tensorflow-cpu","ranges":[">=2.3.0 <2.3.3"],"fixed":["2.3.3"]},{"ecosystem":"PyPI","name":"tensorflow-cpu","purl":"pkg:pypi/tensorflow-cpu","ranges":[">=2.4.0 <2.4.2"],"fixed":["2.4.2"]},{"ecosystem":"PyPI","name":"tensorflow-gpu","purl":"pkg:pypi/tensorflow-gpu","ranges":["<2.1.4"],"fixed":["2.1.4"]},{"ecosystem":"PyPI","name":"tensorflow-gpu","purl":"pkg:pypi/tensorflow-gpu","ranges":[">=2.2.0 <2.2.3"],"fixed":["2.2.3"]},{"ecosystem":"PyPI","name":"tensorflow-gpu","purl":"pkg:pypi/tensorflow-gpu","ranges":[">=2.3.0 <2.3.3"],"fixed":["2.3.3"]},{"ecosystem":"PyPI","name":"tensorflow-gpu","purl":"pkg:pypi/tensorflow-gpu","ranges":[">=2.4.0 <2.4.2"],"fixed":["2.4.2"]}]},{"id":"PYSEC-2021-187","url":"https://osv.dev/vulnerability/PYSEC-2021-187","summary":"","modified":"2023-12-06T01:01:05.505669Z","packages":[{"ecosystem":"PyPI","name":"tensorflow","purl":"pkg:pypi/tensorflow","ranges":["<2.2.0rc0",">=2.2.0 <2.3.0rc0",">=2.3.0 <2.3.4",">=2.4.0 <2.4.3"],"fixed":["2.2.0rc0","2.3.0rc0","2.3.4","2.4.3"]}]},{"id":"PYSEC-2021-478","url":"https://osv.dev/vulnerability/PYSEC-2021-478","summary":"","modified":"2023-12-06T01:01:05.505669Z","packages":[{"ecosystem":"PyPI","name":"tensorflow-cpu","purl":"pkg:pypi/tensorflow-cpu","ranges":["<2.2.0rc0",">=2.2.0 <2.3.0rc0",">=2.3.0 <2.3.4",">=2.4.0 <2.4.3"],"fixed":["2.2.0rc0","2.3.0rc0","2.3.4","2.4.3"]}]},{"id":"PYSEC-2021-676","url":"https://osv.dev/vulnerability/PYSEC-2021-676","summary":"","modified":"2023-12-06T01:01:05.505669Z","packages":[{"ecosystem":"PyPI","name":"tensorflow-gpu","purl":"pkg:pypi/tensorflow-gpu","ranges":["<2.2.0rc0",">=2.2.0 <2.3.0rc0",">=2.3.0 <2.3.4",">=2.4.0 <2.4.3"],"fixed":["2.2.0rc0","2.3.0rc0","2.3.4","2.4.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}