CVE-2023-1428 is a high-severity (CVSS 7.5) Reachable Assertion vulnerability in io.grpc:grpc-protobuf. A fix is available for io.grpc:grpc-protobuf — see the affected versions and patch details below.
Denial-of-Service in gRPC
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-1428.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-1428 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
io.grpc:grpc-protobuf🐍grpcio💎grpcReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven, PyPI, RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
There exists an vulnerability causing an abort() to be called in gRPC. The following headers cause gRPC's C++ implementation to abort() when called via http2:
te: x (x != trailers)
:scheme: x (x != http, https)
grpclb_client_stats: x (x == anything)
On top of sending one of those headers, a later header must be sent that gets the total header size past 8KB. We recommend upgrading past git commit 2485fa94bd8a723e5c977d55a3ce10b301b437f8 or v1.53 and above.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.grpc:grpc-protobuf | ≥ 1.51.0&&< 1.53.0 | 1.53.0io.grpc:grpc-protobuf:1.53.0 |
| 🐍PyPI | grpcio | ≥ 1.51.0&&< 1.53.0 | 1.53.0pip install --upgrade 'grpcio==1.53.0' |
| 💎RubyGems | grpc | ≥ 1.51.0&&< 1.53.0 | 1.53.0bundle update grpc --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.grpc:grpc-protobuf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.grpc:grpc-protobuf to 1.53.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-1428 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-1428 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-1428. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability is specific to the C++, Python and Ruby implementations of gRPC prior to the 1.53 release. The gRPC library was packaged with Openshift via the Kuryr component. However, Kuryr was never configured to run code using the gRPC library and has since been removed.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 9 | rhc-worker-playbook-0:0.1.10-1.el9_5 | RHSA-2024:10761 |
Frequently Asked Questions
Is CVE-2023-1428 in your dependencies?
O3 Security finds CVE-2023-1428 across Maven, PyPI, RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.