Security advisory

{
  "id": "b49fce02ee718b06e0fe32985a485a0f5859f46565fb302561111c2e6b55c530",
  "url": "https://osv.dev/vulnerability/CVE-2021-37681",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-37681",
    "summary": "TensorFlow is an end-to-end open source platform for machine learning. In affected versions the implementation of SVDF in TFLite is [vulnerable to a null pointer error](https://github.com/tensorflow/tensorflow/blob/460e000de3a83278fb00b61a16d161b1964f15f4/tensorflow/lite/kernels/svdf.cc#L300-L313). The [`GetVariableInput` function](https://github.com/tensorflow/tensorflow/blob/460e000de3a83278fb00b61a16d161b1964f15f4/tensorflow/lite/kernels/kernel_util.cc#L115-L119) can return a null pointer but `GetTensorData` assumes that the argument is always a valid tensor. Furthermore, because `GetVariableInput` calls [`GetMutableInput`](https://github.com/tensorflow/tensorflow/blob/460e000de3a83278fb00b61a16d161b1964f15f4/tensorflow/lite/kernels/kernel_util.cc#L82-L90) which might return `nullptr`, the `tensor->is_variable` expression can also trigger a null pointer exception. We have patched the issue in GitHub commit 5b048e87e4e55990dae6b547add4dae59f4e1c76. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.",
    "evidence": "osv:CVE-2021-37681",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-37681",
      "aliases": [
        "BIT-tensorflow-2021-37681",
        "CVE-2021-37681",
        "GHSA-7xwj-5r4v-429p",
        "PYSEC-2021-303",
        "PYSEC-2021-594",
        "PYSEC-2021-792"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/tensorflow/tensorflow",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b36436b087bd8e8701ef51718179037cccdfc26e"
                },
                {
                  "fixed": "7462dcaae1e8cfe1dfd0c62dd6083f9749a9d827"
                },
                {
                  "introduced": "582c8d236cb079023657287c318ff26adb239002"
                },
                {
                  "fixed": "4c0b84bf2a714bcdd18da1f1f94d533d72399d52"
                },
                {
                  "introduced": "a4dfb8d1a71385bd6d122e4f27f86dcebb96712d"
                },
                {
                  "last_affected": "5368d50428b30b7c9ccd038aec65d09252d16596"
                },
                {
                  "fixed": "5b048e87e4e55990dae6b547add4dae59f4e1c76"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.3.0"
                      },
                      {
                        "fixed": "2.3.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.4.0"
                      },
                      {
                        "fixed": "2.4.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:2.5.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.5.0"
                      },
                      {
                        "last_affected": "2.5.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:2.6.0:rc0:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.6.0-rc0"
                      },
                      {
                        "last_affected": "2.6.0-rc0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:2.6.0:rc1:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.6.0-rc1"
                      },
                      {
                        "last_affected": "2.6.0-rc1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tensorflow:2.6.0:rc2:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.6.0-rc2"
                      },
                      {
                        "last_affected": "2.6.0-rc2"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "5b048e87e4e55990dae6b547add4dae59f4e1c76"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.5.0",
            "2.6.0-rc0",
            "2.6.0-rc1",
            "2.6.0-rc2",
            "v2.3.3",
            "v2.4.2",
            "v2.3.2",
            "v2.4.1",
            "v2.4.0",
            "v2.3.1",
            "v2.3.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-37681.json",
            "vanir_signatures": [
              {
                "id": "CVE-2021-37681-02a04b81",
                "digest": {
                  "length": 3763,
                  "function_hash": "277771564071844196417094966686928471885"
                },
                "source": "https://github.com/tensorflow/tensorflow/commit/5b048e87e4e55990dae6b547add4dae59f4e1c76",
                "target": {
                  "file": "tensorflow/lite/kernels/svdf.cc",
                  "function": "Eval"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
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                "id": "CVE-2021-37681-33364e90",
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                "source": "https://github.com/tensorflow/tensorflow/commit/5b048e87e4e55990dae6b547add4dae59f4e1c76",
                "target": {
                  "file": "tensorflow/lite/kernels/svdf.cc"
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                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-37681-41806392",
                "digest": {
                  "length": 169,
                  "function_hash": "99754822290123940257327233292511093096"
                },
                "source": "https://github.com/tensorflow/tensorflow/commit/5b048e87e4e55990dae6b547add4dae59f4e1c76",
                "target": {
                  "file": "tensorflow/lite/kernels/kernel_util.cc",
                  "function": "GetVariableInput"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-37681-e23df497",
                "digest": {
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                  "line_hashes": [
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                },
                "source": "https://github.com/tensorflow/tensorflow/commit/5b048e87e4e55990dae6b547add4dae59f4e1c76",
                "target": {
                  "file": "tensorflow/lite/kernels/kernel_util.cc"
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                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
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            ],
            "vanir_signatures_modified": "2026-10-20T14:28:19Z"
          }
        }
      ],
      "modified": "2026-10-20T14:28:19.197797192Z",
      "provider": "osv",
      "references": [
        "https://github.com/tensorflow/tensorflow/security/advisories/GHSA-7xwj-5r4v-429p",
        "https://github.com/tensorflow/tensorflow/commit/5b048e87e4e55990dae6b547add4dae59f4e1c76"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-37681",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 389036,
  "published_at": "2021-08-12T22:15:08.867+00:00"
}