Security readout for executives and security teams
Plain-English summary
CVE-2021-45946 is a memory-safety flaw in Wasm3 0.5.0. A malformed WebAssembly input could cause Wasm3 to write outside expected memory during compilation logic. Business urgency depends on whether Wasm3 0.5.0 is used where untrusted WebAssembly is processed.
Executive priority
Treat as a targeted dependency risk, not a broad emergency, unless Wasm3 0.5.0 handles untrusted WebAssembly in business-critical systems. Lack of scoring and patch detail makes inventory and vendor confirmation the immediate priority.
Technical view
The record describes an out-of-bounds write in Wasm3 0.5.0 in CompileBlock, called from Compile_LoopOrBlock and CompileBlockStatements. The supplied sources do not provide CVSS, CWE mapping, patch details, or confirmed exploitation conditions.
Likely exposure
Exposure is most likely where Wasm3 0.5.0 is embedded in applications, services, tooling, or firmware that process WebAssembly. The source bundle does not identify downstream products or broader affected version ranges.
Exploitation context
The CVE is not listed as KEV, and the supplied sources do not report active exploitation. The available evidence appears tied to OSS-Fuzz discovery, which supports a crash or memory-corruption finding but not real-world exploitation.
Researcher notes
Public data is sparse. The key technical fact is an out-of-bounds write in CompileBlock-related compilation paths. Do not assume exploitability, affected downstream products, or remediation status without checking Wasm3 project guidance and local build provenance.
Mitigation direction
- Inventory applications and components that embed Wasm3.
- Confirm whether Wasm3 version 0.5.0 is present.
- Check Wasm3 or OSS-Fuzz guidance for fixed versions.
- Avoid processing untrusted WebAssembly until remediation is confirmed.
- Prioritize updates where Wasm3 handles external inputs.
Validation and detection
- Search SBOMs and dependency manifests for Wasm3.
- Verify runtime or bundled Wasm3 version strings.
- Review WebAssembly processing paths for untrusted input exposure.
- Check vendor advisories before declaring remediation complete.
- Document any compensating controls around WebAssembly ingestion.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2021-45946 mapping review
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Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/wasm3/OSV-2021-678.yamlCVE reference · x_refsource_MISC
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33555CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.