CVE-2021-23894
📋 TL;DR
This vulnerability allows remote unauthenticated attackers to execute arbitrary code on McAfee Database Security servers by sending malicious Java serialized objects. Successful exploitation grants administrator privileges and enables reverse shell creation. All DBSec servers running versions prior to 4.8.2 are affected.
💻 Affected Systems
- McAfee Database Security (DBSec)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the DBSec server with administrator privileges, allowing attackers to pivot to other systems, exfiltrate sensitive database security data, and maintain persistent access.
Likely Case
Remote code execution leading to data theft, installation of malware, or use of the compromised server as a foothold for lateral movement within the network.
If Mitigated
Limited impact if proper network segmentation and access controls prevent unauthenticated external access to DBSec servers.
🎯 Exploit Status
The vulnerability is actively exploited in the wild and requires minimal technical skill to weaponize due to available proof-of-concept code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.8.2
Vendor Advisory: https://kc.mcafee.com/corporate/index?page=content&id=SB10359
Restart Required: Yes
Instructions:
1. Download DBSec 4.8.2 from McAfee support portal. 2. Backup current configuration. 3. Stop DBSec services. 4. Install the update. 5. Restart services. 6. Verify functionality.
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict network access to DBSec servers to only trusted management IP addresses
iptables -A INPUT -p tcp --dport [DBSEC_PORT] -s [TRUSTED_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport [DBSEC_PORT] -j DROP
Windows Firewall Rule
windowsCreate Windows Firewall rule to restrict DBSec port access
New-NetFirewallRule -DisplayName "Block DBSec External" -Direction Inbound -LocalPort [DBSEC_PORT] -Protocol TCP -Action Block
🧯 If You Can't Patch
- Isolate DBSec servers in a dedicated VLAN with strict access controls
- Implement network-based intrusion prevention systems (IPS) to detect and block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check DBSec version via web interface or configuration files. Versions below 4.8.2 are vulnerable.Check Version:
Check web interface at https://[DBSEC_SERVER]:[PORT]/ or examine installation directory version filesVerify Fix Applied:
Verify version shows 4.8.2 or higher in DBSec administration interface and test functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors in DBSec logs
- Unexpected process creation from DBSec service
- Reverse shell connection attempts from DBSec server
Network Indicators:
- Malformed Java serialized objects sent to DBSec ports
- Outbound connections from DBSec server to unknown external IPs
SIEM Query:
source="DBSec" AND ("deserialization" OR "ClassNotFoundException" OR "InvalidClassException") OR process_name="cmd.exe" OR "bash" parent_process="java"