cbcvebase.
CVE-2021-39219
published 2021-09-17

CVE-2021-39219: 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…

PriorityP429medium6.3CVSS 3.1
AVLACHPRLUINSUCNIHAH
EPSS
0.29%
21.1th percentile
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 ensur

Affected

13 ranges
VendorProductVersion rangeFixed in
bytecodealliancewasmtime< 0.30.00.30.0
bytecodealliancewasmtime<= 0.29.0
bytecodealliancewasmtime>= 0 < 101998733b74624cbd348a2366d05760b40181f3101998733b74624cbd348a2366d05760b40181f3
bytecodealliancewasmtime>= 0 < 0.30.00.30.0
bytecodealliancewasmtime>= 0 < 398a73f0dd862dbe703212ebae8e34036a18c11c398a73f0dd862dbe703212ebae8e34036a18c11c
bytecodealliancewasmtime>= 0 < b39f087414f27ae40c44449ed5d1154e03449bffb39f087414f27ae40c44449ed5d1154e03449bff
bytecodealliancewasmtime>= 0 < 0.30.00.30.0
bytecodealliancewasmtime>= 0.0.0-0 < 0.30.00.30.0
bytecodealliancewasmtime>= 0.26.0 < 0.30.00.30.0
bytecodealliancewasmtime>= 0.26.0 < 0.30.00.30.0
debianrust-wasmtime
fedoraprojectfedora
fedoraprojectfedora

CVSS provenance

nvdv3.16.3MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
nvdv2.03.3LOWAV:L/AC:M/Au:N/C:N/I:P/A:P
vendor_debian6.3LOW
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