CVE-2021-26914
📋 TL;DR
CVE-2021-26914 is a critical Java deserialization vulnerability in NetMotion Mobility Server's MvcUtil component that allows unauthenticated remote attackers to execute arbitrary code with SYSTEM privileges. This affects organizations running vulnerable versions of NetMotion Mobility Server before patches were applied. Successful exploitation leads to complete system compromise.
💻 Affected Systems
- NetMotion Mobility Server
📦 What is this software?
Netmotion Mobility by Netmotionsoftware
Netmotion Mobility by Netmotionsoftware
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with SYSTEM privileges, enabling data theft, lateral movement, ransomware deployment, and persistent backdoor installation.
Likely Case
Remote code execution leading to initial foothold, credential harvesting, and installation of malware or cryptocurrency miners.
If Mitigated
Attack blocked at network perimeter or detected before significant damage occurs.
🎯 Exploit Status
Public exploit code available since February 2021. Exploitation is straightforward with available tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 11.73 or 12.02 and later
Vendor Advisory: https://www.netmotionsoftware.com/security-advisories/security-vulnerability-in-mobility-web-server-november-19-2020
Restart Required: Yes
Instructions:
1. Download appropriate patch version (11.73+ or 12.02+) from NetMotion support portal. 2. Backup configuration and data. 3. Apply patch following vendor instructions. 4. Restart Mobility services. 5. Verify successful update.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to Mobility Server web interface to trusted networks only
Use firewall rules to block external access to Mobility Server ports (typically 443/8443)
Application Layer Filtering
allImplement WAF rules to block Java deserialization payloads
Configure WAF to block requests containing serialized Java objects or known exploit patterns
🧯 If You Can't Patch
- Isolate the Mobility Server in a dedicated network segment with strict access controls
- Implement intrusion detection/prevention systems to monitor for exploit attempts and block malicious traffic
🔍 How to Verify
Check if Vulnerable:
Check Mobility Server version in administration console or via 'MobilityServer.exe --version' commandCheck Version:
MobilityServer.exe --versionVerify Fix Applied:
Confirm version is 11.73 or higher (for 11.x) or 12.02 or higher (for 12.x)📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors in Mobility Server logs
- Unexpected process creation with SYSTEM privileges
- Suspicious network connections from Mobility Server
Network Indicators:
- HTTP POST requests to MvcUtil endpoints with serialized Java objects
- Unusual outbound connections from Mobility Server
SIEM Query:
source="mobility_server.log" AND ("deserialization" OR "MvcUtil" OR "valueStringToObject")🔗 References
- http://packetstormsecurity.com/files/162617/NetMotion-Mobility-Server-MvcUtil-Java-Deserialization.html
- https://ssd-disclosure.com/?p=4676
- https://ssd-disclosure.com/ssd-advisory-netmotion-mobility-server-multiple-deserialization-of-untrusted-data-lead-to-rce/
- https://www.netmotionsoftware.com/security-advisories/security-vulnerability-in-mobility-web-server-november-19-2020
- http://packetstormsecurity.com/files/162617/NetMotion-Mobility-Server-MvcUtil-Java-Deserialization.html
- https://ssd-disclosure.com/?p=4676
- https://ssd-disclosure.com/ssd-advisory-netmotion-mobility-server-multiple-deserialization-of-untrusted-data-lead-to-rce/
- https://www.netmotionsoftware.com/security-advisories/security-vulnerability-in-mobility-web-server-november-19-2020
