CVE-2020-37196: Dnss Domain Name Search DoS Vulnerability

CVE-2020-37196 Overview

CVE-2020-37196 is a denial of service vulnerability in Dnss Domain Name Search Software that allows attackers to crash the application by providing an oversized registration key. This buffer overflow vulnerability (CWE-120) can be triggered by generating a 1000-character buffer payload and pasting it into the registration key field, causing an immediate application crash.

Critical Impact

Local attackers can cause application denial of service by exploiting improper input validation in the registration key field, disrupting software availability.

Affected Products

• Dnss Domain Name Search Software

Discovery Timeline

• 2026-02-11 - CVE CVE-2020-37196 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2020-37196

Vulnerability Analysis

This vulnerability exists due to a classic buffer overflow condition (CWE-120: Buffer Copy without Checking Size of Input) in the registration key validation routine of Dnss Domain Name Search Software. The application fails to properly validate the length of user-supplied input before copying it into a fixed-size buffer, allowing attackers to trigger a denial of service condition.

The attack requires local access and user interaction, as the malicious payload must be manually pasted into the registration key field within the application's user interface. When the oversized input is processed, it overwrites adjacent memory locations, causing the application to crash.

Root Cause

The root cause is improper input validation and lack of boundary checking when handling the registration key field. The application allocates a fixed-size buffer for the registration key but does not verify that the input length falls within acceptable bounds before processing. When a 1000-character payload is provided, the buffer overflow corrupts stack or heap memory, leading to application termination.

Attack Vector

The attack vector is local, requiring an attacker to have access to the system where Dnss Domain Name Search Software is installed. The exploitation process involves:

1. Generating an oversized payload (approximately 1000 characters)
2. Opening the Dnss Domain Name Search Software application
3. Navigating to the registration key input field
4. Pasting the malicious payload into the field
5. The application crashes due to buffer overflow

This vulnerability has been documented in Exploit-DB #47856, which provides details on the exploitation technique. Additional information is available in the VulnCheck Advisory on DNS Issues.

Detection Methods for CVE-2020-37196

Indicators of Compromise

• Unexpected crashes or termination of Dnss Domain Name Search Software
• Application crash logs showing memory access violations or stack buffer overflows
• Presence of unusually long strings in clipboard history or input fields

Detection Strategies

• Monitor application event logs for crash events related to Dnss Domain Name Search Software
• Implement endpoint detection rules to identify buffer overflow attack patterns
• Deploy application whitelisting to control execution of vulnerable software versions

Monitoring Recommendations

• Enable crash dump collection for forensic analysis of application failures
• Configure endpoint protection to alert on repeated application crashes
• Review system logs for signs of local exploitation attempts

How to Mitigate CVE-2020-37196

Immediate Actions Required

• Check with the vendor (NSA Auditor Tool) for available security patches or updates
• Restrict access to systems running the vulnerable software to trusted users only
• Consider removing or disabling the software if it is not essential to operations
• Implement application-level input validation where possible

Patch Information

No specific patch information is currently available from the vendor. Organizations should monitor the vendor website for security updates and apply patches as soon as they become available.

Workarounds

• Limit local access to systems running Dnss Domain Name Search Software to authorized personnel only
• Implement endpoint protection solutions that can detect and block buffer overflow attempts
• Consider using alternative domain name search tools that do not have this vulnerability
• Educate users about the risks of pasting untrusted content into application fields

# Example: Restrict application access using file system permissions (Windows)
# Run as Administrator to limit who can execute the vulnerable application
icacls "C:\Program Files\Dnss\dnss.exe" /inheritance:r /grant:r Administrators:RX