Security advisory

{
  "id": "26a872d2077d0ab1471da17245abcadf2f2c731c38daa0000c12a80aa87a3a84",
  "url": "https://osv.dev/vulnerability/CVE-2021-29550",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-29550",
    "summary": "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 an",
    "evidence": "osv:CVE-2021-29550",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-29550",
      "aliases": [
        "BIT-tensorflow-2021-29550",
        "CVE-2021-29550",
        "GHSA-f78g-q7r4-9wcv",
        "PYSEC-2021-187",
        "PYSEC-2021-478",
        "PYSEC-2021-676"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/tensorflow/tensorflow",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0931ea3d985bb9c8fdd054a5e29c4129623c849b"
                },
                {
                  "introduced": "2b96f3662bd776e277f86997659e61046b56c315"
                },
                {
                  "fixed": "cfe0c80169ae984bcdc99ff6de7444164aaa8e07"
                },
                {
                  "introduced": "b36436b087bd8e8701ef51718179037cccdfc26e"
                },
                {
                  "fixed": "3929ffacfbef7c431e8397920d040aaf47acff19"
                },
                {
                  "introduced": "582c8d236cb079023657287c318ff26adb239002"
                },
                {
                  "fixed": "1923123d32ea41d92b70a27a3f6ecf0763b56f6c"
                },
                {
                  "fixed": "548b5eaf23685d86f722233d8fbc21d0a4aecb96"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.1.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.2.0"
                      },
                      {
                        "fixed": "2.2.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.3.0"
                      },
                      {
                        "fixed": "2.3.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.4.0"
                      },
                      {
                        "fixed": "2.4.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "548b5eaf23685d86f722233d8fbc21d0a4aecb96"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.1.3",
            "v2.2.2",
            "v2.3.2",
            "v2.4.1",
            "v2.1.2",
            "v2.2.1",
            "v2.4.0",
            "v2.3.1",
            "v2.2.0",
            "v2.1.1",
            "v2.3.0",
            "v2.1.0",
            "v2.1.0-rc0",
            "v2.1.0-rc2",
            "v2.1.0-rc1",
            "v1.12.1",
            "v1.9.0-rc2",
            "v1.6.0-rc1",
            "v1.1.0-rc2",
            "v1.1.0-rc1",
            "0.6.0",
            "0.5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-29550.json",
            "vanir_signatures": [
              {
                "id": "CVE-2021-29550-681b9ee2",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
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                },
                "source": "https://github.com/tensorflow/tensorflow/commit/548b5eaf23685d86f722233d8fbc21d0a4aecb96",
                "target": {
                  "file": "tensorflow/core/kernels/fractional_avg_pool_op.cc"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T14:24:25Z"
          }
        }
      ],
      "modified": "2026-10-20T14:24:25.649386989Z",
      "provider": "osv",
      "references": [
        "https://github.com/tensorflow/tensorflow/commit/548b5eaf23685d86f722233d8fbc21d0a4aecb96",
        "https://github.com/tensorflow/tensorflow/security/advisories/GHSA-f78g-q7r4-9wcv"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-29550",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388908,
  "published_at": "2021-05-14T20:15:12.897+00:00"
}