CVE-2024-6876
📋 TL;DR
An out-of-bounds read vulnerability in the OSCAT Basic Library used in CODESYS PLC systems allows local unprivileged attackers to read limited internal PLC data, potentially causing service crashes. This affects industrial control systems using vulnerable CODESYS components. Attackers need local access to exploit this vulnerability.
💻 Affected Systems
- CODESYS Control runtime systems
- CODESYS Development System
- Systems using OSCAT Basic Library
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Service crash leading to PLC disruption and potential industrial process interruption in critical infrastructure environments.
Likely Case
Limited information disclosure of PLC internal data and potential denial of service through application crashes.
If Mitigated
Minimal impact with proper network segmentation and access controls limiting local attacker access.
🎯 Exploit Status
Requires local access to the system. No public exploit code available at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Specific versions listed in CODESYS advisory VDE-2024-046
Vendor Advisory: https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=18601&token=27389a52e058d95ff70b17a2370fedf07e073034&download=
Restart Required: Yes
Instructions:
1. Review CODESYS advisory VDE-2024-046. 2. Identify affected CODESYS components in your environment. 3. Apply vendor-provided patches. 4. Restart affected PLCs and control systems. 5. Verify patch installation.
🔧 Temporary Workarounds
Network Segmentation
allIsolate PLC systems from general network access to limit local attack surface
Access Control Hardening
allRestrict local user access to PLC systems and implement least privilege principles
🧯 If You Can't Patch
- Implement strict network segmentation to isolate PLC systems from untrusted networks
- Apply principle of least privilege and restrict local user access to critical control systems
🔍 How to Verify
Check if Vulnerable:
Check CODESYS component versions against advisory VDE-2024-046. Review system logs for unexpected crashes or access attempts.Check Version:
Check CODESYS Control runtime version through CODESYS development environment or system administration toolsVerify Fix Applied:
Verify CODESYS component versions match patched versions from vendor advisory. Test system stability and monitor for crashes.📡 Detection & Monitoring
Log Indicators:
- Unexpected PLC service crashes
- Access attempts to OSCAT library components
- Memory access violations in system logs
Network Indicators:
- Unusual local network traffic to PLC systems
- Multiple connection attempts to control system services
SIEM Query:
source="plc_logs" AND (event_type="crash" OR event_type="memory_violation") AND component="OSCAT"