Vulnerability in wasmtime (CVE-2023-41880)

Summary

Vulnerability in wasmtime (CVE-2023-41880). Risk of unauthorized operations or information disclosure. Exploitable via i64x2.shr_s. Mitigation: upgrade to 12.0.2 or later.

Original description

The description as published by the source.

Impact

Wasmtime versions from 10.0.0 to 12.0.1 contain a miscompilation of the WebAssembly i64x2.shr_s instruction on x86_64 platforms when the shift amount is a constant value that is larger than 32. Only x86_64 is affected so all other targets are not affected by this. The miscompilation results in the instruction producing an incorrect result, namely the low 32-bits of the second lane of the vector are derived from the low 32-bits of the second lane of the input vector instead of the high 32-bits. The primary impact of this issue is that any WebAssembly program using the i64x2.shr_s with a constant shift amount larger than 32 may produce an incorrect result.

This issue is not an escape from the WebAssembly sandbox. Execution of WebAssembly guest programs will still behave correctly with respect to memory sandboxing and isolation from the host. Wasmtime considers non-spec-compliant behavior as a security issue nonetheless.

This issue was discovered through fuzzing of Wasmtime's code generator Cranelift.

Patches

Wasmtime versions 10.0.2, 11.0.2, and 12.0.2 are all patched to no longer have this miscompilation.

Workarounds

This issue only affects x86_64 hosts and the only workaround is to either scan for this pattern in wasm modules which is nontrivial or to disable the SIMD proposal for WebAssembly. Users prior to 10.0.0 are unaffected by this vulnerability.

References…

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-2023-41880 has been found in wasmtime.
Attackers can target a specific entry point like i64x2.shr_s over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade wasmtime to 12.0.2 or later.
If unsure, ask your IT team or search "wasmtime CVE-2023-41880" on the vendor's site.

CVE-2023-41880 (wasmtime) — CWE-193
Attack vector: remote (network-reachable) / no user interaction
Attack surface: i64x2.shr_s
Patched: 12.0.2 — apply immediately
Workaround: This issue only affects x86_64 hosts and the only workaround is to either scan for this pattern in wasm modules which is nontrivial or to [disable the SIMD proposal for WebAssembly](https://docs.rs/wasmtime/latest/wasmtime/struct.Config.html#method.w
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.

❓ What is the problem

A vulnerability (CWE-193) exists in wasmtime. Attackers reach the vulnerable code path via i64x2.shr_s.

📍 Affected scope

Check the vendor advisory for the affected versions of wasmtime. Attack surface: i64x2.shr_s.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 12.0.2.

🛡️ Workaround

Workaround: This issue only affects x86_64 hosts and the only workaround is to either scan for this pattern in wasm modules which is nontrivial or to [disable the SIMD proposal for WebAssembly](https://docs.rs/wasmtime/latest/wasmtime/struct.Config.html#method.w

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'wasmtime' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'wasmtime' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で wasmtime を grep し、稼働しているサービス・バージョンを把握する。
2
Apply temporary workaround mitigate
```
This issue only affects x86_64 hosts and the only workaround is to either scan for this pattern in wasm modules which is nontrivial or to [disable the SIMD proposal for WebAssembly](https://docs.rs/wasmtime/latest/wasmtime/struct.Config.html#method.w
```
パッチが適用されるまでの応急処置として、This issue only affects x86_64 hosts and the only workaround is to either scan for this pattern in wasm modules which is nontrivial or to [disable the SIMD proposal for WebAssembly](https://docs.rs/wasmtime/latest/wasmtime/struct.Config.html#method.w を実施。回避策の副作用 (機能低下) を確認した上で。
3
Apply patch patch
```
Upgrade wasmtime to 12.0.2
```
ステージング環境で 12.0.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
4
Post-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。

Affected packages

crates.io wasmtime

[{"type":"SEMVER","events":[{"introduced":"12.0.0"},{"fixed":"12.0.2"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2023-41880 rust-wasmtime Fixed in: 15.0.0+dfsg-1

References

advisory nvd.nist.gov
package github.com
web github.com
web github.com
web github.com
web github.com
web docs.rs
web rustsec.org