# CVE-2023-41880: Miscompilation of wasm `i64x2.shr_s` instruction with constant input on x86_64 > Wasmtime miscompiles specific SIMD instructions on x86_64, causing incorrect results in WebAssembly programs without breaking sandbox isolation. - **Severity:** Low 2.2 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 15 Sep 2023 - **Updated:** 24 Sep 2024 - **Also known as:** DEBIAN-CVE-2023-41880, GHSA-gw5p-q8mj-p7gh, RUSTSEC-2023-0091 ## What is CVE-2023-41880? CVE-2023-41880 is a low-severity vulnerability in bytecodealliance wasmtime, published on 15 Sep 2023. An attacker needs administrator access to exploit it, with no action from the victim. ### Official description Wasmtime is a standalone runtime for WebAssembly. Wasmtime versions from 10.0.0 to versions 10.02, 11.0.2, and 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. Wasmtime versions 10.0.2, 11.0.2, and 12.0.2 are all patched to no longer have this miscompilation. 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. Weakness: CWE-193 (Off-by-one Error) ## Which versions are affected by CVE-2023-41880? 7 open source packages ship an affected version, including wasmtime. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `wasmtime` | crates.io | From 0.0.0-0 | 10.0.2, 11.0.2, 12.0.2 | | `wasmtime` | crates.io | From 10.0.0 | 10.0.2 | | `wasmtime` | crates.io | From 10.0.0 | 10.0.2 | | `wasmtime` | crates.io | From 11.0.0 | 11.0.2 | | `wasmtime` | crates.io | From 11.0.0 | 11.0.2 | | `wasmtime` | crates.io | From 12.0.0 | 12.0.2 | | `wasmtime` | crates.io | From 12.0.0 | 12.0.2 | Products: Bytecodealliance Wasmtime. ## How do I fix CVE-2023-41880? Upgrade wasmtime to a fixed version for your release line: 10.0.2, 11.0.2 or 12.0.2. ## Is CVE-2023-41880 being exploited? There is no known exploitation of CVE-2023-41880 in the wild and no public exploit code. ## Other vulnerabilities in bytecodealliance wasmtime - [CVE-2026-34971](https://insights.sbomify.com/CVE-2026-34971/): Wasmtime miscompiled guest heap access enables sandbox escape on aarch64 Cranelift (critical 9.0) - [CVE-2026-34987](https://insights.sbomify.com/CVE-2026-34987/): Wasmtime with Winch compiler backend on aarch64 may allow a sandbox-escaping memory access (critical 9.0) - [CVE-2022-39393](https://insights.sbomify.com/CVE-2022-39393/): Wasmtime vulnerable to data leakage between instances in the pooling allocator (high 8.6) - [CVE-2022-24791](https://insights.sbomify.com/CVE-2022-24791/): Use after free in Wasmtime (high 8.1) - [CVE-2026-47261](https://insights.sbomify.com/CVE-2026-47261/): Wasmtime: WASI path_open(TRUNCATE) bypasses `FilePerms::WRITE` host restriction (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-41880 and fix it if it is affected. What it is: CVE-2023-41880 is a low-severity vulnerability in bytecodealliance wasmtime, published on 15 Sep 2023. An attacker needs administrator access to exploit it, with no action from the victim. Exploitation: There is no known exploitation of CVE-2023-41880 in the wild and no public exploit code. Affected packages and fixed versions: - wasmtime (crates.io): affected from 0.0.0-0; fixed in 10.0.2, 11.0.2, 12.0.2 - wasmtime (crates.io): affected from 10.0.0; fixed in 10.0.2 - wasmtime (crates.io): affected from 10.0.0; fixed in 10.0.2 - wasmtime (crates.io): affected from 11.0.0; fixed in 11.0.2 - wasmtime (crates.io): affected from 11.0.0; fixed in 11.0.2 - wasmtime (crates.io): affected from 12.0.0; fixed in 12.0.2 - wasmtime (crates.io): affected from 12.0.0; fixed in 12.0.2 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-41880/ (Markdown: https://insights.sbomify.com/CVE-2023-41880/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-41880 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-41880 - OSV: https://osv.dev/vulnerability/CVE-2023-41880 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-41880/ Summaries are generated and may contain mistakes; the official description above is the record.