CVE-2020-4521
📋 TL;DR
CVE-2020-4521 is a remote code execution vulnerability in IBM Maximo Asset Management caused by unsafe Java deserialization. An authenticated attacker can send specially crafted requests to execute arbitrary code on affected systems. This affects IBM Maximo Asset Management versions 7.6.0 and 7.6.1.
💻 Affected Systems
- IBM Maximo Asset Management
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to install malware, steal sensitive data, pivot to other systems, or disrupt operations.
Likely Case
Attacker gains shell access to the Maximo server, potentially accessing database credentials and sensitive asset management data.
If Mitigated
With proper network segmentation and authentication controls, impact limited to the Maximo application server.
🎯 Exploit Status
Exploitation requires valid credentials but uses well-known Java deserialization techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply Interim Fix 7.6.1.2 or later
Vendor Advisory: https://www.ibm.com/support/pages/node/6332587
Restart Required: Yes
Instructions:
1. Download Interim Fix 7.6.1.2 from IBM Fix Central. 2. Stop Maximo application server. 3. Apply the fix according to IBM documentation. 4. Restart Maximo application server. 5. Verify fix applied successfully.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to Maximo application to trusted networks only
Authentication Hardening
allImplement strong authentication controls and monitor for suspicious login attempts
🧯 If You Can't Patch
- Isolate Maximo servers from internet and restrict internal access to authorized users only
- Implement application-level firewall rules to block suspicious serialized object patterns
🔍 How to Verify
Check if Vulnerable:
Check Maximo version via Admin Console or by examining installation files. If version is 7.6.0 or 7.6.1 without Interim Fix 7.6.1.2, system is vulnerable.Check Version:
Check Maximo System Properties in Admin Console or examine maximo.properties fileVerify Fix Applied:
Verify Interim Fix 7.6.1.2 or later is installed via Maximo Admin Console or by checking fix installation logs.📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors in application logs
- Suspicious requests containing serialized objects
- Unexpected process execution from Maximo application
Network Indicators:
- HTTP requests with serialized Java objects in parameters
- Unusual outbound connections from Maximo server
SIEM Query:
source="maximo_logs" AND ("deserialization" OR "ObjectInputStream" OR "readObject")