{"schema_version":"1.7.5","id":"GHSA-mhhc-q96p-mfm9","published":"2021-08-25T14:39:58Z","modified":"2026-07-08T06:28:29.862814155Z","aliases":["BIT-tensorflow-2021-37686","CVE-2021-37686","PYSEC-2021-308","PYSEC-2021-599","PYSEC-2021-797"],"summary":"Infinite loop in TFLite","details":"### Impact\nThe strided slice implementation in TFLite has a logic bug which can allow an attacker to trigger an infinite loop. This arises from newly introduced support for [ellipsis in axis definition](https://github.com/tensorflow/tensorflow/blob/149562d49faa709ea80df1d99fc41d005b81082a/tensorflow/lite/kernels/strided_slice.cc#L103-L122):\n\n```cc\n  for (int i = 0; i < effective_dims;) {\n    if ((1 << i) & op_context->params->ellipsis_mask) {\n      // ...\n      int ellipsis_end_idx =\n          std::min(i + 1 + num_add_axis + op_context->input_dims - begin_count,\n                   effective_dims);\n      // ...\n      for (; i < ellipsis_end_idx; ++i) {\n        // ...\n      }\n      continue;\n    }\n    // ...\n    ++i;\n  }\n```\n\nAn attacker can craft a model such that `ellipsis_end_idx` is smaller than `i` (e.g., always negative). In this case, the inner loop does not increase `i` and the `continue` statement causes execution to skip over the preincrement at the end of the outer loop.\n\n### Patches\nWe have patched the issue in GitHub commit [dfa22b348b70bb89d6d6ec0ff53973bacb4f4695](https://github.com/tensorflow/tensorflow/commit/dfa22b348b70bb89d6d6ec0ff53973bacb4f4695).\n\nThe fix will be included in TensorFlow 2.6.0. This is the only affected version.\n\n### For more information\nPlease 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.\n\n### Attribution\nThis vulnerability has been reported by members of the Aivul Team from Qihoo 360.","affected":[{"package":{"name":"tensorflow","ecosystem":"PyPI","purl":"pkg:pypi/tensorflow"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.0rc0"},{"fixed":"2.6.0rc2"}]}],"versions":["2.6.0rc0","2.6.0rc1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-mhhc-q96p-mfm9/GHSA-mhhc-q96p-mfm9.json"}},{"package":{"name":"tensorflow-cpu","ecosystem":"PyPI","purl":"pkg:pypi/tensorflow-cpu"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.0rc0"},{"fixed":"2.6.0rc2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-mhhc-q96p-mfm9/GHSA-mhhc-q96p-mfm9.json"}},{"package":{"name":"tensorflow-gpu","ecosystem":"PyPI","purl":"pkg:pypi/tensorflow-gpu"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.0rc0"},{"fixed":"2.6.0rc2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-mhhc-q96p-mfm9/GHSA-mhhc-q96p-mfm9.json"}}],"references":[{"type":"WEB","url":"https://github.com/tensorflow/tensorflow/security/advisories/GHSA-mhhc-q96p-mfm9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-37686"},{"type":"WEB","url":"https://github.com/tensorflow/tensorflow/commit/dfa22b348b70bb89d6d6ec0ff53973bacb4f4695"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/tensorflow-cpu/PYSEC-2021-599.yaml"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/tensorflow-gpu/PYSEC-2021-797.yaml"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/tensorflow/PYSEC-2021-308.yaml"},{"type":"PACKAGE","url":"https://github.com/tensorflow/tensorflow"},{"type":"WEB","url":"https://github.com/tensorflow/tensorflow/releases/tag/v2.3.4"},{"type":"WEB","url":"https://github.com/tensorflow/tensorflow/releases/tag/v2.4.3"},{"type":"WEB","url":"https://github.com/tensorflow/tensorflow/releases/tag/v2.5.1"},{"type":"WEB","url":"https://github.com/tensorflow/tensorflow/releases/tag/v2.6.0"}],"database_specific":{"cwe_ids":["CWE-835"],"github_reviewed":true,"github_reviewed_at":"2021-08-24T17:54:33Z","nvd_published_at":"2021-08-12T22:15:00Z","severity":"MODERATE"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}