CVE-2023-51661
HIGHCVE-2023-51661 is a high-severity (CVSS 8.4) CWE-284 vulnerability in wasmer-cli. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2023-51661 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Filesystem sandbox not enforced in wasmer-cli
Blast Radius
wasmer-cliReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Wasmer is a WebAssembly runtime that enables containers to run anywhere: from Desktop to the Cloud, Edge and even the browser. Wasm programs can access the filesystem outside of the sandbox. Service providers running untrusted Wasm code on Wasmer can unexpectedly expose the host filesystem. This vulnerability has been patched in version 4.2.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | wasmer-cli | ≥ 3.0.0&&< 4.2.4 | 4.2.4 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wasmer-cli. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update wasmer-cli to 4.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-51661 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-51661 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-51661. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-51661 in your dependencies?
O3 detects CVE-2023-51661 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.