CVE-2020-36435 is a high-severity (CVSS 8.1) CWE-362 vulnerability in ruspiro-singleton. O3 Security confirms whether CVE-2020-36435 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Data race in ruspiro-singleton
Real-World Exposure
ruspiro-singletonReal-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
Singleton<T> is meant to be a static object that can be initialized lazily. In
order to satisfy the requirement that static items must implement Sync,
Singleton implemented both Sync and Send unconditionally.
This allows for a bug where non-Sync types such as Cell can be used in
singletons and cause data races in concurrent programs.
The flaw was corrected in commit b0d2bd20e by adding trait bounds, requiring
the contaiend type to implement Sync.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | ruspiro-singleton | all versions | 0.4.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ruspiro-singleton. 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 ruspiro-singleton to 0.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-36435 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-2020-36435 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-2020-36435. 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-2020-36435 in your dependencies?
O3 detects CVE-2020-36435 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.