CVE intelligence and bounded remediation

CVE-2023-27477 — wasmtime is a fast and secure runtime for WebAssembly

Medium CVSS 4.3

wasmtime is a fast and secure runtime for WebAssembly. Wasmtime's code generation backend, Cranelift, has a bug on x86_64 platforms for the WebAssembly `i8x16.select` instruction which will produce the wrong results when the same operand is provided to the instruction and some of the selected indices are greater than 16. There is an off-by-one error in the calculation of the mask to the `pshufb` instruction which causes incorrect results to be returned if lanes are selected from the second vector. This codegen bug has been fixed in Wasmtiem 6.0.1, 5.0.1, and 4.0.1. Users are recommended to upgrade to these updated versions. If upgrading is not an option for you at this time, you can avoid this miscompilation by disabling the Wasm simd proposal. Additionally the bug is only present on x86_64 hosts. Other platforms such as AArch64 and s390x are not affected.

Severity
Medium
CVSS
4.3 (3.1)
Published
2023-03-08
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-193

Affected products

  • bytecodealliance / cranelift-codegen
  • bytecodealliance / cranelift-codegen / 0.92.0
  • bytecodealliance / cranelift-codegen / 0.93.0
  • bytecodealliance / wasmtime
  • bytecodealliance / wasmtime / 5.0.0
  • bytecodealliance / wasmtime / 6.0.0

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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