CVE-2021-47771
📋 TL;DR
CVE-2021-47771 is a denial of service vulnerability in RDP Manager 4.9.9.3 where local attackers can crash the application by entering oversized text in connection name and server fields. This affects users of RDP Manager 4.9.9.3 on Windows systems, potentially requiring full reinstallation after exploitation.
💻 Affected Systems
- RDP Manager
📦 What is this software?
Rdp Manager by Cinspiration
⚠️ Risk & Real-World Impact
Worst Case
Permanent application crash requiring complete reinstallation, disrupting RDP management operations and causing data loss of unsaved connection configurations.
Likely Case
Application freeze and crash requiring restart, temporarily disrupting RDP management capabilities.
If Mitigated
Minimal impact with proper input validation and user privilege restrictions in place.
🎯 Exploit Status
Exploitation requires local access to the application interface. Proof-of-concept code is publicly available on Exploit-DB and other sources.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if available, or use workarounds.
🔧 Temporary Workarounds
Restrict User Input
windowsImplement input validation to limit field lengths in connection configuration
Not applicable - requires code modification
Application Sandboxing
windowsRun RDP Manager with restricted privileges to limit impact
RunAs /user:StandardUser "C:\Path\To\RDPManager.exe"
🧯 If You Can't Patch
- Restrict access to RDP Manager to trusted users only
- Implement application monitoring to detect crash events and alert administrators
🔍 How to Verify
Check if Vulnerable:
Check RDP Manager version in Help > About. If version is 4.9.9.3, the system is vulnerable.Check Version:
Check application version through Help > About menu or examine executable propertiesVerify Fix Applied:
Test by attempting to enter oversized text (over 1000 characters) in Verbindungsname or Server fields. If application doesn't crash, fix is working.📡 Detection & Monitoring
Log Indicators:
- Application crash logs
- Windows Event Logs showing RDP Manager process termination
Network Indicators:
- None - this is a local attack
SIEM Query:
EventID=1000 OR EventID=1001 AND ProcessName="RDPManager.exe"