CVE-2021-37181
📋 TL;DR
This vulnerability allows unauthenticated attackers to execute arbitrary code on affected systems by exploiting insecure deserialization in Siemens Cerberus DMS and Desigo CC products. The flaw exists in the CCOM communication component used for client connectivity, affecting multiple versions of these building management systems. Attackers can achieve remote code execution without authentication.
💻 Affected Systems
- Cerberus DMS
- Desigo CC Compact
- Desigo CC
📦 What is this software?
Desigo Cc by Siemens
Desigo Cc by Siemens
Desigo Cc by Siemens
Desigo Cc by Siemens
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code, potentially leading to data theft, system disruption, or lateral movement within the network.
Likely Case
Remote code execution enabling attackers to install malware, create backdoors, or disrupt building management operations.
If Mitigated
Limited impact if systems are isolated, patched, or have network controls preventing exploitation attempts.
🎯 Exploit Status
Insecure deserialization vulnerabilities are commonly exploited and weaponized. The unauthenticated nature and high CVSS score make this attractive to attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Cerberus DMS V5.0 QU1 and later; Desigo CC Compact V5.0 QU1 and later; Desigo CC V5.0 QU1 and later
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-453715.pdf
Restart Required: Yes
Instructions:
1. Download the QU1 update from Siemens support portal. 2. Apply the update to all affected systems. 3. Restart the application/services. 4. Verify the update was successful.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected systems from untrusted networks and limit access to only necessary connections.
Disable Vulnerable Components
windowsDisable CCOM communication component if not required for operations.
🧯 If You Can't Patch
- Implement strict network access controls to limit connections to affected systems
- Monitor for exploitation attempts and anomalous behavior on affected systems
🔍 How to Verify
Check if Vulnerable:
Check product version against affected versions list. Verify if CCOM component is enabled.Check Version:
Check version through product administration interface or consult Siemens documentation for version verification.Verify Fix Applied:
Confirm system is running Cerberus DMS V5.0 QU1 or later, Desigo CC Compact V5.0 QU1 or later, or Desigo CC V5.0 QU1 or later.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation
- Abnormal network connections from CCOM component
- Deserialization errors or exceptions
Network Indicators:
- Unexpected traffic to CCOM ports
- Malformed serialized data packets
SIEM Query:
Process creation from Cerberus/Desigo services OR network connections to CCOM ports from untrusted sources