Wasmtime: Panic lowering a host-created component model stream into a guest that expects a different payload type

Overview

Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or an equivalent typed reader. A malicious guest that controls exported function types or returned values can cause the host to pass the type-erased value to a guest expecting a different payload type, which panics the Wasmtime host. This issue is fixed in versions 48.0.7 and 49.0.4.

Affected

• wasmtime >= 46.0.0, < 48.0.7
• wasmtime >= 49.0.0, < 49.0.4

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.