CVE-2020-37197
📋 TL;DR
CVE-2020-37197 is a buffer overflow vulnerability in Dnss Domain Name Search Software that allows attackers to cause denial of service by crashing the application. Attackers can exploit this by sending overly long input to the 'Name' field during registration. This affects all users running vulnerable versions of the software.
💻 Affected Systems
- Dnss Domain Name Search Software
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete application crash leading to service disruption, potentially affecting domain name search functionality for all users.
Likely Case
Application crashes when malicious input is received, requiring manual restart and causing temporary service interruption.
If Mitigated
With input validation controls, the attack would be blocked before reaching the vulnerable code.
🎯 Exploit Status
Exploit code is publicly available and requires minimal technical skill to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor website for latest version
Vendor Advisory: http://www.nsauditor.com/
Restart Required: Yes
Instructions:
1. Visit http://www.nsauditor.com/
2. Download latest version of Dnss Domain Name Search Software
3. Install the update
4. Restart the application
🔧 Temporary Workarounds
Input Validation Filter
allImplement input validation to restrict 'Name' field length to reasonable limits
Implement input validation in application code: if len(name_input) > 100: reject_input()
Network Filtering
allBlock or monitor traffic containing suspiciously long registration requests
🧯 If You Can't Patch
- Disable registration functionality if not required
- Implement web application firewall (WAF) rules to block requests with overly long 'Name' parameters
🔍 How to Verify
Check if Vulnerable:
Test by entering a 1000+ character string in the registration name field and observe if application crashesCheck Version:
Check Help > About in the application interfaceVerify Fix Applied:
Attempt the same buffer overflow test after patching - application should handle input gracefully📡 Detection & Monitoring
Log Indicators:
- Application crash logs
- Error messages related to buffer overflow or memory access violations
- Unusually long input strings in registration logs
Network Indicators:
- HTTP POST requests with 'Name' parameter exceeding normal length (1000+ characters)
- Multiple rapid registration attempts
SIEM Query:
source="application_logs" AND ("buffer overflow" OR "access violation" OR "crash") AND process="dnss.exe"