Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type…
Summary
Vulnerability reported (CVE-2021-39219). Data can be tampered with by attackers. Exploitable via wasmtime.
Original description
The description as published by the source.
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…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-39219 has been found.
Attackers can target a specific entry point like wasmtime over the network to misuse the product.
Data can be tampered with by attackers.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2021-39219" on the vendor's site.
CVE-2021-39219
Attack vector: local / no user interaction
Attack surface: wasmtime / unsafe / Engine / Linker
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) has been reported. Attackers reach the vulnerable code path via wasmtime.
Check the vendor advisory for the affected versions. Attack surface: wasmtime / unsafe / Engine / Linker.
Severity: ?. Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- patch github.com
- web crates.io
- web lists.fedoraproject.org
- web lists.fedoraproject.org