CVE-2020-37187 Overview
CVE-2020-37187 is a denial of service vulnerability affecting SpotDialup version 1.6.7. The flaw resides in the registration Name input field, which fails to validate input length. An attacker can paste a 1000-character buffer payload into the field, causing the application to crash. The issue is classified under CWE-120: Buffer Copy without Checking Size of Input. Exploitation requires local access and user interaction with the registration interface. Public exploit code is available through Exploit-DB #47904 and the VulnCheck Advisory for SpotDialup.
Critical Impact
A locally interacting attacker can crash SpotDialup 1.6.7 by submitting an oversized string in the registration Name field, resulting in loss of application availability.
Affected Products
- SpotDialup 1.6.7
- Distributions bundled with the affected SpotDialup build
- Systems where SpotDialup 1.6.7 is installed and reachable for local interaction
Discovery Timeline
- 2026-02-11 - CVE-2020-37187 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2020-37187
Vulnerability Analysis
The vulnerability stems from missing input length validation on the registration Name field in SpotDialup 1.6.7. When the application processes the field, it copies the supplied string into a fixed-size buffer without verifying the source length. Submitting approximately 1000 characters overruns the destination buffer and causes the process to terminate. The condition aligns with [CWE-120], a classic buffer copy without checking size of input. The recorded EPSS data indicates an extremely low real-world exploitation probability, consistent with the local attack vector and limited impact.
Root Cause
The underlying defect is improper bounds checking when reading user-supplied data from the registration dialog. The application allocates a finite buffer for the Name value but copies the input using an unbounded routine. This pattern matches the boundary condition error category, where the program trusts the size of an attacker-controlled string.
Attack Vector
Exploitation requires local access to the SpotDialup interface and active user interaction. The attacker generates a 1000-character payload, opens the registration form, and pastes the buffer into the Name field. Upon submission or field processing, SpotDialup crashes. The published proof of concept on Exploit-DB demonstrates the crash without privilege escalation or remote control.
No verified exploit code is reproduced here. Refer to Exploit-DB #47904 for the original proof of concept that demonstrates payload generation and the crash sequence.
Detection Methods for CVE-2020-37187
Indicators of Compromise
- Unexpected SpotDialup process termination shortly after registration form interaction.
- Windows Application event log entries referencing a crashed SpotDialup executable with an access violation.
- Creation of Windows Error Reporting (WER) crash dumps tied to the SpotDialup binary.
Detection Strategies
- Monitor process termination events for the SpotDialup binary and correlate with active user sessions.
- Inspect Application and System event logs for repeated faulting module entries pointing at SpotDialup.
- Track foreground window focus on the registration dialog immediately preceding a crash event.
Monitoring Recommendations
- Forward endpoint process and crash telemetry to a centralized log platform for correlation.
- Alert on multiple crashes of SpotDialup from the same host within a short window.
- Review clipboard-paste activity on hosts running SpotDialup if user-reported crashes occur.
How to Mitigate CVE-2020-37187
Immediate Actions Required
- Restrict local interactive access to systems running SpotDialup 1.6.7 to trusted users only.
- Remove SpotDialup 1.6.7 from endpoints where it is not operationally required.
- Educate users to report unexpected SpotDialup crashes after entering registration data.
Patch Information
No vendor patch is referenced in the available advisory data. Consult the NSA Auditor Homepage and the VulnCheck Advisory for SpotDialup for any updated vendor guidance or successor builds.
Workarounds
- Uninstall SpotDialup 1.6.7 on systems where it is non-essential.
- Apply application allow-listing to prevent unprivileged users from executing the affected binary.
- Limit who can open the registration dialog through OS-level user permission scoping.
# Configuration example: locate and remove the affected binary on Windows
where SpotDialup.exe
# Then uninstall via the registered uninstaller in:
# HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
