CVE-2021-22797
📋 TL;DR
This path traversal vulnerability in Schneider Electric's industrial control software allows attackers to deploy malicious scripts to unauthorized locations by loading a specially crafted project file. Successful exploitation could lead to remote code execution on engineering workstations. Affected users include those running vulnerable versions of EcoStruxure Control Expert, EcoStruxure Process Expert, and SCADAPack RemoteConnect software.
💻 Affected Systems
- EcoStruxure Control Expert
- EcoStruxure Process Expert
- SCADAPack RemoteConnect for x70
📦 What is this software?
Ecostruxure Control Expert by Schneider Electric
Ecostruxure Process Expert by Schneider Electric
Remoteconnect by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of engineering workstation leading to potential lateral movement into operational technology networks, manipulation of industrial processes, and disruption of critical infrastructure.
Likely Case
Local code execution on the engineering workstation, potentially allowing theft of intellectual property, manipulation of control logic, or deployment of additional malware.
If Mitigated
Attack fails due to proper file validation, limited user privileges, or network segmentation preventing malicious project file delivery.
🎯 Exploit Status
Exploitation requires the user to load a malicious project file, which could be delivered via social engineering, compromised repositories, or supply chain attacks.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: EcoStruxure Control Expert: V15.0 SP2 or later; EcoStruxure Process Expert: 2021 or later; SCADAPack RemoteConnect: Contact Schneider Electric for updates
Vendor Advisory: https://www.se.com/ww/en/download/document/SEVD-2021-257-01/
Restart Required: Yes
Instructions:
1. Download the appropriate update from Schneider Electric's security advisory. 2. Backup existing projects and configurations. 3. Install the update following vendor instructions. 4. Restart the system. 5. Verify the installation and test functionality.
🔧 Temporary Workarounds
Restrict project file sources
allOnly load project files from trusted, verified sources and implement strict file validation procedures.
User privilege reduction
windowsRun engineering software with limited user privileges to reduce impact of successful exploitation.
🧯 If You Can't Patch
- Implement network segmentation to isolate engineering workstations from production networks and internet access.
- Deploy application whitelisting to prevent execution of unauthorized scripts and binaries.
🔍 How to Verify
Check if Vulnerable:
Check software version against affected versions list. For EcoStruxure Control Expert: Help > About; for EcoStruxure Process Expert: check version in application interface.Check Version:
No single command - check through application interface or Windows Programs and Features.Verify Fix Applied:
Verify installed version is patched: EcoStruxure Control Expert V15.0 SP2 or later, EcoStruxure Process Expert 2021 or later.📡 Detection & Monitoring
Log Indicators:
- Failed project file loading attempts
- Unusual file system access patterns
- Execution of unexpected scripts or binaries
Network Indicators:
- Unusual network connections from engineering workstations
- Transfer of project files from untrusted sources
SIEM Query:
EventID=4688 AND (ProcessName LIKE '%ControlExpert%' OR ProcessName LIKE '%ProcessExpert%') AND CommandLine CONTAINS 'project' AND (SourceAddress NOT IN [trusted_ips])