Security advisory

{
  "id": "cb016cfee5ea701883f397875d0060816a45ded78a4c53b2917516f5ad68f584",
  "url": "https://osv.dev/vulnerability/CVE-2021-39219",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-39219",
    "summary": "Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the `wasmtime` crate clearly marks which functions are safe and which are `unsafe`, guaranteeing that if consumers never use `unsafe` then it should not be possible to have memory unsafety issues in their embeddings of Wasmtime. An issue was discovered in the safe API of `Linker::func_*` APIs. These APIs were previously not sound when one `Engine` was used to create the `Linker` and then a different `Engine` was used to create a `Store` and then the `Linker` was used to instantiate a module into that `Store`. Cross-`Engine` usage of functions is not supported in Wasmtime and this can result in type confusion of function pointers, resulting in being able to safely call a function with the wrong type. Triggering this bug requires using at least two `Engine` values in an embedding and then additionally using two different values with a `Linker` (one at the creation time of the `Linker` and another when instantiating a module with the `Linker`). It's expected that usage of more-than-one `Engine` in an embedding is relatively rare since an `Engine` is intended to be a globally shared resource, so the expectation is that the impact of this issue is relatively small. The fix implemented is to change this behavior to `panic!()` in Rust instead of silently allowing it. Using different `Engine` instances with a `Linker` is a programm",
    "evidence": "osv:CVE-2021-39219",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-39219",
      "aliases": [
        "CVE-2021-39216",
        "CVE-2021-39218",
        "CVE-2021-39219",
        "GHSA-4873-36h9-wv49",
        "GHSA-q879-9g95-56mx",
        "GHSA-v4cp-h94r-m7xf",
        "PYSEC-2021-320",
        "PYSEC-2021-321",
        "PYSEC-2021-322",
        "RUSTSEC-2021-0110"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/bytecodealliance/wasmtime",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "572fbc8c54b5a9519154c57e28b86cfaaba57bbb"
                },
                {
                  "fixed": "b39f087414f27ae40c44449ed5d1154e03449bff"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.30.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b39f087414f27ae40c44449ed5d1154e03449bff"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.29.0",
            "v0.28.0",
            "v0.27.0",
            "v0.26.0",
            "v0.25.0",
            "v0.24.0",
            "v0.23.0",
            "v0.22.0",
            "cranelift-v0.69.0",
            "v0.21.0",
            "v0.20.0",
            "v0.19.0",
            "v0.18.0",
            "v0.17.0",
            "v0.16.0",
            "cranelift-v0.61.0",
            "cranelift-v0.60.0",
            "v0.12.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-39219.json"
          }
        }
      ],
      "modified": "2026-10-24T10:50:42.673939142Z",
      "provider": "osv",
      "references": [
        "https://crates.io/crates/wasmtime",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAVBRYDDUIY2ZR3K3FO4BVYJKIMJ5TP7/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z2Z33FTXFQ6EOINVEQIP4DFBG53G5XIY/",
        "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-q879-9g95-56mx",
        "https://github.com/bytecodealliance/wasmtime/commit/b39f087414f27ae40c44449ed5d1154e03449bff"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
              "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  },
                  {
                    "introduced": "35"
                  },
                  {
                    "last_affected": "35"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-39216",
        "evidence": "/aliases"
      },
      {
        "value": "CVE-2021-39218",
        "evidence": "/aliases"
      },
      {
        "value": "CVE-2021-39219",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 442508,
  "published_at": "2021-09-17T20:15:07.763+00:00"
}