CVE-2021-35215
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary code on SolarWinds Orion Platform servers through insecure deserialization. It affects organizations running Orion Platform version 2020.2.5, requiring authentication but enabling remote code execution with high impact.
💻 Affected Systems
- SolarWinds Orion Platform
📦 What is this software?
Orion Platform by Solarwinds
⚠️ 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
Attackers gain administrative control over the Orion server, enabling data theft, credential harvesting, and lateral movement within the network.
If Mitigated
With proper network segmentation and authentication controls, impact is limited to the Orion server itself.
🎯 Exploit Status
ZDI-21-1245 advisory includes technical details; authentication required but Orion credentials are often known or guessable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2020.2.6 or later
Vendor Advisory: https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35215
Restart Required: Yes
Instructions:
1. Download Orion Platform 2020.2.6 or later from SolarWinds Customer Portal. 2. Run installer with administrative privileges. 3. Follow upgrade wizard. 4. Restart Orion services after completion.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to Orion Platform to only trusted administrative networks
Authentication Hardening
allEnforce strong passwords, multi-factor authentication, and account lockout policies
🧯 If You Can't Patch
- Implement strict network access controls to limit Orion Platform access to essential personnel only
- Monitor Orion Platform logs for unusual authentication attempts or deserialization errors
🔍 How to Verify
Check if Vulnerable:
Check Orion Platform version in web interface under Settings > All Settings > Product InformationCheck Version:
Not applicable - check via Orion web interfaceVerify Fix Applied:
Verify version is 2020.2.6 or higher in Product Information page📡 Detection & Monitoring
Log Indicators:
- Unusual authentication patterns
- Deserialization errors in Orion logs
- Unexpected process creation
Network Indicators:
- Unusual outbound connections from Orion server
- Suspicious PowerShell or command execution patterns
SIEM Query:
source="orion_logs" AND ("deserialization" OR "remote code" OR "unexpected process")🔗 References
- https://documentation.solarwinds.co/enm/success_center/orionplatform/content/release_notes/orion_platform_2020-2-6_release_notes.htm
- https://documentation.solarwinds.com/en/success_center/orionplatform/content/core-secure-configuration.htm
- https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35215
- https://www.zerodayinitiative.com/advisories/ZDI-21-1245/
- https://documentation.solarwinds.co/enm/success_center/orionplatform/content/release_notes/orion_platform_2020-2-6_release_notes.htm
- https://documentation.solarwinds.com/en/success_center/orionplatform/content/core-secure-configuration.htm
- https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35215
- https://www.zerodayinitiative.com/advisories/ZDI-21-1245/
