CVE-2020-37204: RemShutdown DoS Vulnerability

CVE-2020-37204 Overview

CVE-2020-37204 is a denial of service vulnerability affecting RemShutdown version 2.9.0.0. The vulnerability exists in the application's registration key input field, where improper input validation allows attackers to crash the application by providing a specially crafted oversized buffer. Attackers can generate a 1000-character payload and paste it into the registration key field to trigger an application crash, resulting in a denial of service condition.

Critical Impact

Attackers can cause application crashes through malformed registration key input, disrupting system administration operations that rely on RemShutdown for remote shutdown capabilities.

Affected Products

• RemShutdown 2.9.0.0

Discovery Timeline

• 2026-02-11 - CVE CVE-2020-37204 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2020-37204

Vulnerability Analysis

This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), commonly known as a classic buffer overflow. The application fails to properly validate the length of user-supplied input in the registration key field before copying it to a fixed-size buffer. When an attacker provides a string exceeding the expected buffer size (approximately 1000 characters), the application fails to handle the oversized input gracefully, leading to memory corruption and subsequent application crash.

The local attack vector requires user interaction, as the malicious payload must be pasted into the registration key dialog. While this limits the attack surface compared to remotely exploitable vulnerabilities, it still poses a risk in scenarios where users may inadvertently paste malicious content or where social engineering tactics are employed.

Root Cause

The root cause of this vulnerability is improper bounds checking in the registration key input handling routine. The application allocates a fixed-size buffer for the registration key but does not validate that user input conforms to expected length constraints before processing. This classic buffer overflow pattern (CWE-120) allows oversized input to overflow the allocated memory region, corrupting adjacent memory and causing the application to crash.

Attack Vector

The attack vector for CVE-2020-37204 is local, requiring an attacker to have access to the system where RemShutdown is installed. The exploitation process involves:

1. The attacker crafts a payload consisting of approximately 1000 or more characters
2. The attacker opens the RemShutdown application and navigates to the registration dialog
3. The malicious payload is pasted into the registration key input field
4. Upon processing the oversized input, the application crashes due to buffer overflow

While user interaction is required, the attack complexity is low and no special privileges are needed beyond the ability to run the application. The impact is limited to availability (denial of service) with no direct confidentiality or integrity impact.

Detection Methods for CVE-2020-37204

Indicators of Compromise

• Unexpected crashes of the RemShutdown.exe process
• Windows Event Log entries showing application faults in RemShutdown with memory access violations
• Repeated application restarts or user complaints about RemShutdown instability

Detection Strategies

• Monitor Windows Application Event Log for crash events involving RemShutdown
• Implement endpoint detection rules to identify abnormal termination of RemShutdown processes
• Deploy memory protection monitoring to detect buffer overflow attempts in legacy applications

Monitoring Recommendations

• Configure Windows Error Reporting to capture and centralize crash dumps for analysis
• Implement application whitelisting policies to control RemShutdown execution in sensitive environments
• Review SentinelOne endpoint telemetry for process crash patterns indicative of exploitation attempts

How to Mitigate CVE-2020-37204

Immediate Actions Required

• Evaluate whether RemShutdown 2.9.0.0 is necessary for operations; consider removal if not critical
• Restrict access to systems where RemShutdown is installed to trusted users only
• Implement application control policies to prevent unauthorized execution
• Consider migrating to alternative remote shutdown utilities with better input validation

Patch Information

No vendor patch information is available in the current CVE data. Review the NSA Auditor Tool Overview for any vendor updates or newer versions that may address this vulnerability. Additionally, the VulnCheck Denial of Service Advisory provides additional technical details about this vulnerability.

Workarounds

• Avoid copying and pasting text from untrusted sources into RemShutdown dialogs
• Run RemShutdown with least-privilege user accounts to limit system-wide impact
• Deploy endpoint protection solutions like SentinelOne to monitor for exploitation attempts
• Consider containerizing or sandboxing the application if continued use is required