CVE-2024-56468
📋 TL;DR
This vulnerability in IBM InfoSphere Data Replication VSAM for z/OS allows remote attackers to cause denial of service by sending specially crafted invalid HTTP requests to the log reading service. It affects IBM InfoSphere Data Replication VSAM for z/OS Remote Source 11.4 installations. The vulnerability requires network access to the affected service.
💻 Affected Systems
- IBM InfoSphere Data Replication VSAM for z/OS Remote Source
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of the log reading service, potentially affecting data replication operations and requiring service restart.
Likely Case
Temporary denial of service affecting log reading functionality, requiring service restart to recover.
If Mitigated
Minimal impact with proper network segmentation and request filtering in place.
🎯 Exploit Status
Exploitation requires sending malformed HTTP requests to the vulnerable service endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply APAR PH65438
Vendor Advisory: https://www.ibm.com/support/pages/node/7239221
Restart Required: Yes
Instructions:
1. Download APAR PH65438 from IBM Fix Central. 2. Apply the fix following IBM installation procedures. 3. Restart the affected service.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to the log reading service to trusted IP addresses only.
Configure firewall rules to limit access to specific source IPs
Request Filtering
allImplement HTTP request validation/filtering at network perimeter.
Configure WAF or proxy to filter malformed HTTP requests
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the vulnerable service
- Deploy web application firewall with HTTP request validation rules
🔍 How to Verify
Check if Vulnerable:
Check if running IBM InfoSphere Data Replication VSAM for z/OS Remote Source 11.4 without APAR PH65438 applied.Check Version:
Check IBM product documentation for version verification commands specific to your installation.Verify Fix Applied:
Verify APAR PH65438 is installed and service is running version with the fix.📡 Detection & Monitoring
Log Indicators:
- Service crash/restart events
- Malformed HTTP request patterns in access logs
- Error messages related to HTTP parsing failures
Network Indicators:
- Multiple malformed HTTP requests to log service endpoint
- Unusual traffic patterns to service port
SIEM Query:
source="*ibm*" AND (event="service restart" OR event="crash") AND service="log_reading"