CVE-2017-9424
📋 TL;DR
CVE-2017-9424 is a remote code execution vulnerability in IdeaBlade Breeze Breeze.Server.NET caused by insecure JSON deserialization using TypeNameHandling. Attackers can exploit this to execute arbitrary code on affected servers. Organizations using Breeze.Server.NET versions before 1.6.5 are vulnerable.
💻 Affected Systems
- IdeaBlade Breeze Breeze.Server.NET
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code, steal data, install malware, or pivot to other systems.
Likely Case
Remote code execution leading to data theft, service disruption, or lateral movement within the network.
If Mitigated
Limited impact with proper network segmentation and input validation, potentially reduced to denial of service.
🎯 Exploit Status
Exploitation is straightforward using known JSON deserialization attack patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.6.5 and later
Vendor Advisory: http://breeze.github.io/doc-net/release-notes.html
Restart Required: Yes
Instructions:
1. Update Breeze.Server.NET to version 1.6.5 or later. 2. Rebuild and redeploy affected applications. 3. Restart application services.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to reject malicious JSON payloads before deserialization.
TypeNameHandling Restriction
allConfigure JSON serialization settings to restrict TypeNameHandling to None or minimal values.
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems from critical assets.
- Deploy web application firewall (WAF) rules to block malicious JSON payloads.
🔍 How to Verify
Check if Vulnerable:
Check application dependencies for Breeze.Server.NET version below 1.6.5.Check Version:
Check package.config or project references for Breeze.Server.NET version.Verify Fix Applied:
Verify Breeze.Server.NET version is 1.6.5 or higher in application dependencies.📡 Detection & Monitoring
Log Indicators:
- Unusual JSON deserialization errors
- Suspicious TypeNameHandling patterns in logs
- Unexpected process execution
Network Indicators:
- Malformed JSON payloads with type information
- Unusual outbound connections from application server
SIEM Query:
source="application_logs" AND ("TypeNameHandling" OR "JSON deserialization" OR "Breeze") AND severity=ERROR