{"id":"PYSEC-2021-322","details":"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 programmer bug that `wasmtime` catches at runtime. This bug has been patched and users should upgrade to Wasmtime version 0.30.0. If you cannot upgrade Wasmtime and are using more than one `Engine` in your embedding it's recommended to instead use only one `Engine` for the entire program if possible. An `Engine` is designed to be a globally shared resource that is suitable to have only one for the lifetime of an entire process. If using multiple `Engine`s is required then code should be audited to ensure that `Linker` is only used with one `Engine`.","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","RUSTSEC-2021-0110"],"modified":"2024-03-15T00:05:20.369060Z","published":"2021-09-17T20:15:00Z","references":[{"type":"WEB","url":"https://crates.io/crates/wasmtime"},{"type":"FIX","url":"https://github.com/bytecodealliance/wasmtime/commit/b39f087414f27ae40c44449ed5d1154e03449bff"},{"type":"ADVISORY","url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-q879-9g95-56mx"}],"affected":[{"package":{"name":"wasmtime","ecosystem":"PyPI","purl":"pkg:pypi/wasmtime"},"ranges":[{"type":"GIT","repo":"https://github.com/bytecodealliance/wasmtime","events":[{"introduced":"0"},{"fixed":"b39f087414f27ae40c44449ed5d1154e03449bff"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.30.0"}]}],"versions":["0.0.1","0.0.2","0.11.0","0.12.0","0.15.0","0.15.1","0.16.0","0.16.1","0.17.0","0.18.0","0.18.1","0.18.2","0.19.0","0.20.0","0.21.0","0.22.0","0.23.0","0.24.0","0.25.0","0.26.0","0.27.0","0.28.0","0.28.1","0.29.0","0.9.0"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/wasmtime/PYSEC-2021-322.yaml"}}],"schema_version":"1.7.3"}