CVE-2019-3564 is a high-severity (CVSS 7.5) CWE-834 vulnerability in github.com/facebook/fbthrift. O3 Security confirms whether CVE-2019-3564 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Input Validation and Excessive Iteration in Go Facebook Thrift
Real-World Exposure
github.com/facebook/fbthriftReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Go Facebook Thrift servers would not error upon receiving messages with containers of fields of unknown type. As a result, malicious clients could send short messages which would take a long time for the server to parse, potentially leading to denial of service. This issue affects Facebook Thrift prior to v2019.03.04.00.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/facebook/fbthrift | all versions | 0.31.1-0.20190225164308-c461c1bd1a3e |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/facebook/fbthrift. 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 github.com/facebook/fbthrift to 0.31.1-0.20190225164308-c461c1bd1a3e or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-3564 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-2019-3564 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-2019-3564. 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-2019-3564 in your dependencies?
O3 detects CVE-2019-3564 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.