CVE-2021-27007
📋 TL;DR
This vulnerability allows an unauthenticated attacker to hijack active Remote Desktop Sessions in NetApp Virtual Desktop Service when used with an HTML5 gateway. Attackers can take over authenticated user sessions without credentials. Organizations using NetApp VDS with HTML5 gateway are affected.
💻 Affected Systems
- NetApp Virtual Desktop Service (VDS)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of all active remote desktop sessions, allowing attackers to access sensitive data, execute commands as authenticated users, and move laterally within the network.
Likely Case
Session hijacking leading to unauthorized access to user desktops, data theft, and potential credential harvesting from active sessions.
If Mitigated
Limited impact if proper network segmentation, session monitoring, and access controls prevent unauthenticated access to the HTML5 gateway interface.
🎯 Exploit Status
The vulnerability allows session takeover without authentication, suggesting relatively straightforward exploitation once the attack vector is understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.0.1004 and later
Vendor Advisory: https://security.netapp.com/advisory/ntap-20211223-0008/
Restart Required: Yes
Instructions:
1. Download VDS version 2.0.0.1004 or later from NetApp Support Site. 2. Backup current VDS configuration. 3. Deploy the updated VDS software following NetApp upgrade procedures. 4. Restart VDS services to apply the patch.
🔧 Temporary Workarounds
Disable HTML5 Gateway
allTemporarily disable the HTML5 gateway component if not essential for operations
Refer to NetApp VDS administration guide for disabling HTML5 gateway
Network Access Restrictions
allRestrict network access to the HTML5 gateway interface using firewall rules
Configure firewall to allow only trusted IP addresses to access VDS HTML5 gateway port
🧯 If You Can't Patch
- Implement strict network segmentation to isolate VDS systems from untrusted networks
- Enable detailed session logging and monitoring for suspicious session takeover activities
🔍 How to Verify
Check if Vulnerable:
Check VDS version in administration console. If version is below 2.0.0.1004 and HTML5 gateway is enabled, the system is vulnerable.Check Version:
Check version in NetApp VDS administration interface or via 'vds-version' command in VDS CLIVerify Fix Applied:
Confirm VDS version is 2.0.0.1004 or higher in administration console and verify HTML5 gateway functionality works without session hijacking.📡 Detection & Monitoring
Log Indicators:
- Multiple session takeover attempts from single IP
- Unauthenticated access to session management endpoints
- Abnormal session creation patterns
Network Indicators:
- Unusual traffic patterns to VDS HTML5 gateway port
- Session hijacking attempts via HTTP requests
SIEM Query:
source="vds-logs" AND (event="session_takeover" OR event="unauthorized_session_access")