CVE-2020-37194: Backup Key Recovery DOS Vulnerability

CVE-2020-37194 Overview

CVE-2020-37194 is a buffer overflow vulnerability affecting Backup Key Recovery version 2.2.5. This denial of service vulnerability allows attackers to crash the application by supplying an overly long registration key. The vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), which occurs when the application fails to properly validate the length of user-supplied input before copying it to a fixed-size buffer.

Critical Impact

Attackers can generate a 1000-character payload file and paste it into the registration key field to trigger an application crash, resulting in complete denial of service for the affected application.

Affected Products

• Backup Key Recovery version 2.2.5
• NSAuditor Products (vendor ecosystem)

Discovery Timeline

• 2026-02-11 - CVE CVE-2020-37194 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2020-37194

Vulnerability Analysis

This vulnerability stems from improper input validation in the registration key processing functionality of Backup Key Recovery 2.2.5. The application fails to implement adequate boundary checks when handling the registration key input field, allowing an attacker to provide an excessively long string that exceeds the allocated buffer size.

When a user pastes a crafted payload of approximately 1000 characters into the registration key field, the application attempts to copy this data into a fixed-size buffer without first verifying that the input length is within acceptable bounds. This classic buffer overflow condition causes memory corruption, leading to an immediate application crash.

The local attack vector requires user interaction, as the malicious payload must be manually entered or pasted into the registration interface. While this limits the attack surface, it still poses a risk in scenarios where an attacker can socially engineer a victim into copying a malicious string or where automated testing tools interact with the application.

Root Cause

The root cause of CVE-2020-37194 is a classic CWE-120 vulnerability: Buffer Copy without Checking Size of Input. The registration key validation routine in Backup Key Recovery 2.2.5 uses an unsafe copy operation that does not verify the source string length before writing to a destination buffer. When the input exceeds the expected maximum length (likely several hundred characters for a typical registration key), the overflow corrupts adjacent memory structures, destabilizing the application and causing it to terminate unexpectedly.

Attack Vector

The attack requires local access and user interaction. An attacker must craft a payload file containing approximately 1000 characters and convince a user to paste this content into the registration key input field. The exploitation process involves:

1. The attacker generates a text file containing a long string (1000+ characters)
2. The victim opens Backup Key Recovery and navigates to the registration dialog
3. The victim pastes the malicious payload into the registration key field
4. The application crashes immediately due to buffer overflow

The vulnerability mechanism involves copying user-supplied registration key data into a fixed-size stack or heap buffer without length validation. When the input exceeds the buffer capacity, adjacent memory is overwritten, corrupting control structures and causing the application to crash. For detailed technical analysis and proof-of-concept information, refer to the Exploit-DB #47864 entry.

Detection Methods for CVE-2020-37194

Indicators of Compromise

• Unexpected application crashes in Backup Key Recovery, particularly when registration-related functions are accessed
• Windows Event Log entries showing application faults with memory access violations
• Presence of text files containing extremely long strings (1000+ characters) on systems where the application is installed
• User reports of application instability when attempting software registration

Detection Strategies

• Monitor for application crash events related to Backup Key Recovery processes
• Implement endpoint detection rules that flag buffer overflow patterns in registration dialogs
• Deploy application crash analysis tools to identify memory corruption signatures
• Use SentinelOne behavioral AI to detect abnormal application termination patterns

Monitoring Recommendations

• Configure Windows Event Forwarding to centralize application crash logs from systems running vulnerable software
• Implement file integrity monitoring on systems with Backup Key Recovery installed to detect unusual payload files
• Review endpoint telemetry for repeated application crash cycles that may indicate active exploitation attempts

How to Mitigate CVE-2020-37194

Immediate Actions Required

• Identify all systems running Backup Key Recovery version 2.2.5 and prioritize them for remediation
• Contact NSAuditor for information regarding patched versions or security updates
• Consider removing or disabling the affected software if it is not critical to business operations
• Educate users about the risks of pasting untrusted content into registration dialogs

Patch Information

No vendor-provided patch information is currently available in the CVE data. Organizations should check the NSA Auditor Main Page for updated software versions that address this vulnerability. Additional technical details can be found in the VulnCheck Advisory on Key Recovery.

Workarounds

• Restrict access to the Backup Key Recovery application to only authorized personnel who require it for business purposes
• Implement application whitelisting policies to control which applications can run on endpoints
• Deploy SentinelOne endpoint protection to detect and prevent exploitation attempts through behavioral analysis
• Train users to avoid pasting content from untrusted sources into application input fields

In lieu of specific mitigation configurations, organizations should implement defense-in-depth strategies including restricting administrative access to systems running vulnerable software, monitoring for abnormal application behavior, and maintaining current endpoint protection solutions.