CVE-2022-28118
📋 TL;DR
CVE-2022-28118 is a critical remote code execution vulnerability in SiteServer CMS v7.x that allows attackers to execute arbitrary code by uploading a malicious plugin. This affects all organizations using vulnerable versions of SiteServer CMS, potentially compromising entire web servers and their data.
💻 Affected Systems
- SiteServer CMS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete server takeover, data theft, ransomware deployment, and lateral movement to other systems in the network.
Likely Case
Website defacement, data exfiltration, backdoor installation for persistent access, and credential harvesting.
If Mitigated
Limited impact with proper network segmentation, web application firewalls, and strict file upload controls.
🎯 Exploit Status
Exploit requires authentication/access to upload plugins. Public proof-of-concept code exists in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to latest version beyond v7.x
Vendor Advisory: https://github.com/siteserver/cms/issues/3386
Restart Required: Yes
Instructions:
1. Backup current installation and database. 2. Download latest SiteServer CMS version. 3. Replace all files with new version. 4. Restart web server. 5. Verify functionality.
🔧 Temporary Workarounds
Disable Plugin Uploads
allTemporarily disable plugin upload functionality until patching can be completed
Modify SiteServer CMS configuration to remove plugin upload permissions
Implement File Upload Restrictions
allConfigure web server to block upload of executable files and validate all uploaded content
Configure web application firewall rules to block suspicious file uploads
🧯 If You Can't Patch
- Isolate SiteServer CMS instance in separate network segment with strict egress filtering
- Implement application allowlisting to prevent execution of unauthorized plugins
🔍 How to Verify
Check if Vulnerable:
Check SiteServer CMS version in admin panel or by examining version files in installation directoryCheck Version:
Check /admin/panel or examine web.config/version.txt files in SiteServer installationVerify Fix Applied:
Verify version is updated beyond v7.x and test plugin upload functionality with safe test files📡 Detection & Monitoring
Log Indicators:
- Unusual plugin uploads, unexpected file creation in plugin directories, execution of suspicious processes
Network Indicators:
- Outbound connections from web server to unknown IPs, unusual traffic patterns from CMS server
SIEM Query:
source="webserver" AND (event="plugin_upload" OR file_extension="dll,exe,php,asp")🔗 References
- http://siteserver.com
- https://github.com/Richard-Tang/SSCMS-PluginShell/blob/main/Detail.md
- https://github.com/siteserver/cms
- https://github.com/siteserver/cms/issues/3386
- http://siteserver.com
- https://github.com/Richard-Tang/SSCMS-PluginShell/blob/main/Detail.md
- https://github.com/siteserver/cms
- https://github.com/siteserver/cms/issues/3386
