CVE-2023-4785 is a high-severity (CVSS 7.5) CWE-248 vulnerability in grpcio. O3 Security confirms whether CVE-2023-4785 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Denial of Service in gRPC Core
Real-World Exposure
grpcio🐍grpcio🐍grpcio💎grpc💎grpc💎grpc💎grpcReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Lack of error handling in the TCP server in Google's gRPC starting version 1.23 on posix-compatible platforms (ex. Linux) allows an attacker to cause a denial of service by initiating a significant number of connections with the server. Note that gRPC C++ Python, and Ruby are affected, but gRPC Java, and Go are NOT affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | grpcio | ≥ 1.55.0&&< 1.55.3 | 1.55.3 |
| 🐍PyPI | grpcio | ≥ 1.54.0&&< 1.54.3 | 1.54.3 |
| 🐍PyPI | grpcio | ≥ 1.53.0&&< 1.53.2 | 1.53.2 |
| 💎RubyGems | grpc | ≥ 1.56.0&&< 1.56.2 | 1.56.2 |
| 💎RubyGems | grpc | ≥ 1.55.0&&< 1.55.3 | 1.55.3 |
| 💎RubyGems | grpc | ≥ 1.54.0&&< 1.54.3 | 1.54.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for grpcio. 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 grpcio to 1.55.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-4785 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-2023-4785 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-2023-4785. 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-2023-4785 in your dependencies?
O3 detects CVE-2023-4785 across PyPI, RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.