CVE-2024-8391
📋 TL;DR
This vulnerability allows attackers to send unlimited size payloads to Vert.x gRPC servers, potentially causing resource exhaustion and denial of service. It affects Eclipse Vert.x versions 4.3.0 through 4.5.9 using the vertx-grpc-server and vertx-grpc-client components. Systems using these vulnerable versions are at risk of service disruption.
💻 Affected Systems
- Eclipse Vert.x gRPC Server
- Eclipse Vert.x gRPC Client
📦 What is this software?
Vert.x by Eclipse
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage through resource exhaustion, potentially leading to system instability or crashes.
Likely Case
Degraded performance or temporary denial of service due to memory/CPU exhaustion from large payloads.
If Mitigated
Limited impact with proper monitoring and resource limits in place.
🎯 Exploit Status
Exploitation requires sending large payloads to gRPC endpoints, which is straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.5.10
Vendor Advisory: https://github.com/eclipse-vertx/vertx-grpc/issues/113
Restart Required: Yes
Instructions:
1. Update Maven/Gradle dependencies to use vertx-grpc-server and vertx-grpc-client version 4.5.10 or later. 2. Rebuild and redeploy your application. 3. Restart affected services.
🔧 Temporary Workarounds
Implement gRPC message size limits
allAdd custom interceptors or handlers to enforce maximum message size limits before processing.
Implement ServerInterceptor with message size validation
Add size checking in request handlers
Network-level rate limiting
allUse load balancers or firewalls to limit request sizes and connection rates.
Configure nginx/apache with client_max_body_size
Set up WAF rules for gRPC traffic
🧯 If You Can't Patch
- Implement network-level controls to limit incoming gRPC message sizes
- Monitor system resources and set up alerts for abnormal memory/CPU usage
🔍 How to Verify
Check if Vulnerable:
Check your pom.xml or build.gradle for io.vertx:vertx-grpc-server or io.vertx:vertx-grpc-client dependencies with versions 4.3.0-4.5.9.Check Version:
mvn dependency:tree | grep vertx-grpc OR gradle dependencies | grep vertx-grpcVerify Fix Applied:
Verify dependencies are updated to version 4.5.10 or later and test with large payloads to confirm rejection.📡 Detection & Monitoring
Log Indicators:
- Unusually large gRPC messages
- Memory exhaustion warnings
- Increased garbage collection activity
- OutOfMemoryError in logs
Network Indicators:
- Large gRPC payloads (over 4MB typical)
- Sudden spikes in network traffic to gRPC ports
- Multiple large requests from single sources
SIEM Query:
source="application.logs" AND ("OutOfMemoryError" OR "gRPC message too large" OR "memory exhaustion")