CVE-2020-37203: Office Product Key Finder DOS Vulnerability

CVE-2020-37203 Overview

Office Product Key Finder 1.5.4 contains a denial of service vulnerability that allows attackers to crash the application by manipulating the registration code input. Attackers can create a specially crafted text file and paste it into the 'Name and Key' field to trigger an application crash. This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), indicating improper handling of user-supplied input that exceeds expected boundaries.

Critical Impact

Local attackers can cause application crashes and service disruption by exploiting improper input validation in the registration code field, potentially disrupting software license management workflows.

Affected Products

• Office Product Key Finder version 1.5.4

Discovery Timeline

• 2026-02-11 - CVE CVE-2020-37203 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2020-37203

Vulnerability Analysis

This denial of service vulnerability stems from a classic buffer overflow condition (CWE-120) in the Office Product Key Finder application. The vulnerability exists within the registration code processing functionality, specifically in the 'Name and Key' input field. When the application processes user input from this field, it fails to properly validate the size of the input data before copying it into a fixed-size buffer. This allows an attacker to provide input that exceeds the expected buffer boundaries.

The local attack vector requires user interaction, meaning the victim must be tricked into pasting malicious content into the vulnerable field. While the immediate impact is limited to application availability (crash), buffer overflow conditions can sometimes be leveraged for more severe exploitation depending on the application's memory layout and security mitigations in place.

Root Cause

The root cause is a buffer copy operation without checking the size of input (CWE-120). The application's registration code validation routine allocates a fixed-size buffer for user input but does not implement proper bounds checking before copying data from the 'Name and Key' field. When specially crafted input exceeding the buffer size is provided, memory corruption occurs, leading to an application crash.

Attack Vector

The attack requires local access and user interaction. An attacker must craft a malicious text file containing oversized or specially formatted input data. The victim then needs to paste this content into the 'Name and Key' registration field. Upon processing the malicious input, the application attempts to copy the data into an undersized buffer, triggering a buffer overflow condition that causes the application to crash.

The attack scenario typically involves social engineering to convince a user to paste the malicious content, or could occur if users copy text from untrusted sources during the registration process. Additional technical details can be found in the Exploit-DB entry #47867.

Detection Methods for CVE-2020-37203

Indicators of Compromise

• Unexpected crashes of the Office Product Key Finder application during registration attempts
• Application crash dump files indicating buffer overflow or access violation errors
• Presence of unusually large text files intended for pasting into the registration field

Detection Strategies

• Monitor for repeated crashes of the OfficeProductKeyFinder.exe process
• Implement endpoint detection rules for buffer overflow indicators in application crash events
• Review Windows Event Logs for application error events related to Office Product Key Finder

Monitoring Recommendations

• Enable application crash monitoring and alerting for the affected software
• Configure SentinelOne endpoint agents to detect and report application crashes with memory corruption signatures
• Monitor clipboard activity for unusually large text content being pasted into applications

How to Mitigate CVE-2020-37203

Immediate Actions Required

• Avoid copying and pasting content from untrusted sources into the Office Product Key Finder registration fields
• Consider using alternative product key management tools until a patch is available
• Restrict access to the vulnerable application to only authorized personnel
• Deploy SentinelOne endpoint protection to detect and respond to exploitation attempts

Patch Information

No official vendor patch information is currently available in the CVE data. Users should monitor the NSA Auditor Tool website for potential software updates. Additionally, consult the VulnCheck Advisory for the latest mitigation guidance.

Workarounds

• Implement application whitelisting to control which applications can process clipboard data
• Train users to avoid pasting content from untrusted sources into application input fields
• Consider running the application in an isolated environment or sandbox when registration is required
• Limit the use of Office Product Key Finder version 1.5.4 and seek alternative solutions for product key recovery needs