CVE-2021-22756
📋 TL;DR
This vulnerability allows attackers to read memory beyond intended boundaries in Schneider Electric's IGSS Definition software when importing malicious CGF files. Successful exploitation could lead to information disclosure or remote code execution. Organizations using IGSS Definition V15.0.0.21140 and prior versions are affected.
💻 Affected Systems
- Schneider Electric IGSS Definition (Def.exe)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with SYSTEM/administrator privileges leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Information disclosure through memory leaks, potentially exposing sensitive data or credentials, with possible denial of service.
If Mitigated
Limited impact with proper network segmentation, file validation, and least privilege controls preventing successful exploitation.
🎯 Exploit Status
Requires user interaction to import malicious CGF file. No public exploit code available at time of advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V15.0.0.21141 or later
Vendor Advisory: http://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-159-01
Restart Required: Yes
Instructions:
1. Download updated version from Schneider Electric website. 2. Backup current configuration. 3. Install update following vendor instructions. 4. Restart system. 5. Verify version is V15.0.0.21141 or later.
🔧 Temporary Workarounds
Restrict CGF file imports
windowsImplement application whitelisting to block CGF file imports or restrict file execution from untrusted sources.
Network segmentation
allIsolate IGSS Definition systems from internet and untrusted networks to prevent external file uploads.
🧯 If You Can't Patch
- Implement strict file validation for CGF imports using external tools or manual review processes.
- Run IGSS Definition with least privilege accounts and enable Windows Defender Application Control.
🔍 How to Verify
Check if Vulnerable:
Check IGSS Definition version via Help > About menu or examine file properties of Def.exe.Check Version:
wmic datafile where name="C:\\Program Files\\IGSS\\Def.exe" get versionVerify Fix Applied:
Verify version is V15.0.0.21141 or later and test CGF file import functionality.📡 Detection & Monitoring
Log Indicators:
- Failed CGF file imports
- Application crashes in IGSS Definition
- Unusual process creation from Def.exe
Network Indicators:
- Unexpected file transfers to IGSS systems
- CGF files from untrusted sources
SIEM Query:
source="windows" AND process="Def.exe" AND (event_id=1000 OR event_id=1001) AND message="*CGF*"