CVE-2020-36444
HIGHCVE-2020-36444 is a high-severity (CVSS 8.1) CWE-362 vulnerability in async-coap. O3 Security confirms whether CVE-2020-36444 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Data races in async-coap
Real-World Exposure
async-coapReal-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
An issue was discovered in the async-coap crate through 2020-12-08 for Rust.
Affected versions of this crate implement Send/Sync for ArcGuard<RC, T> with no trait bounds on RC. This allows users to send RC: !Send to other threads and also allows users to concurrently access Rc: !Sync from multiple threads.
This can result in memory corruption from data race or other undefined behavior caused by sending T: !Send to other threads (e.g. dropping MutexGuard<T> in another thread that didn't lock its mutex).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | async-coap | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for async-coap. 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.
Remediation status
No patched version of async-coap has shipped for CVE-2020-36444 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2020-36444 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-2020-36444. 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-2020-36444 in your dependencies?
O3 detects CVE-2020-36444 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.