CVE-2021-22519
📋 TL;DR
CVE-2021-22519 is a critical remote code execution vulnerability in Micro Focus SiteScope monitoring software. Remote attackers can execute arbitrary code on affected installations without authentication. This affects all SiteScope versions from 11.40 through 2020.10(11.93).
💻 Affected Systems
- Micro Focus SiteScope
📦 What is this software?
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
Sitescope by Microfocus
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install malware, steal sensitive data, pivot to other systems, and maintain persistent access.
Likely Case
Initial foothold leading to ransomware deployment, data exfiltration, or use as a pivot point for lateral movement within the network.
If Mitigated
Limited impact if proper network segmentation and least-privilege access controls prevent lateral movement and data access.
🎯 Exploit Status
The vulnerability allows remote code execution without authentication, making exploitation straightforward for attackers who discover the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2021.05 (11.94) or later
Vendor Advisory: https://softwaresupport.softwaregrp.com/doc/KM03811028
Restart Required: Yes
Instructions:
1. Download SiteScope 2021.05 (11.94) or later from Micro Focus support portal. 2. Backup current configuration and data. 3. Stop SiteScope services. 4. Install the updated version. 5. Restart SiteScope services. 6. Verify functionality.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to SiteScope instances to only trusted IP addresses and networks.
Use firewall rules to limit access: iptables -A INPUT -p tcp --dport [SiteScope_port] -s [trusted_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport [SiteScope_port] -j DROP
🧯 If You Can't Patch
- Isolate SiteScope instances in a dedicated network segment with strict firewall rules limiting inbound and outbound connections.
- Implement network-based intrusion detection/prevention systems to monitor for exploitation attempts and block malicious traffic.
🔍 How to Verify
Check if Vulnerable:
Check SiteScope version via web interface or configuration files. If version matches affected range, system is vulnerable.Check Version:
Check SiteScope web interface or configuration files for version information. On Windows: Check installed programs list. On Linux: Check SiteScope installation directory for version files.Verify Fix Applied:
Verify SiteScope version is 2021.05 (11.94) or later and test monitoring functionality remains operational.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from SiteScope service account
- Suspicious network connections originating from SiteScope host
- Unexpected file modifications in SiteScope directories
Network Indicators:
- Unusual outbound connections from SiteScope server
- Traffic patterns indicating command and control communication
- Exploitation attempts against SiteScope ports
SIEM Query:
source="SiteScope" AND (event_type="process_creation" AND process_name NOT IN ("expected_processes")) OR (event_type="network_connection" AND dest_ip NOT IN ("allowed_ips"))