# CVE-2020-37199: Nsasoft NBMonitor buffer overflow in registration key input

Source: https://junglewise.ai/threats/cve-2020-37199-nsasoft-nbmonitor-buffer-overflow-in-registration-key-input  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-11. Updated: 2026-06-29  
License: CC BY 4.0 with a link back

CVE-2020-37199 · Severity: high · CVSS 7.5 · Published 2026-02-11

NBMonitor, a network bandwidth monitoring tool, contains a flaw that allows the application to be crashed by entering an excessively long registration key. An attacker or user can trigger this by pasting a 1,000-character string into the license activation field. This results in a denial-of-service condition where the software becomes unresponsive or closes unexpectedly, potentially disrupting network monitoring activities.

Vendors: [Nsasoft](https://junglewise.ai/threats/vendors/nsasoft).

## Quick answers

**Is CVE-2020-37199 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2020-37199 being exploited in the wild.

**How severe is CVE-2020-37199?** High severity, with a CVSS score of 7.5, published 11 February 2026.

**Which products and versions are affected?** Nsasoft Nbmonitor 1.6.6.0 and earlier.

**Is there a fix for CVE-2020-37199?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2020-37199 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2020-37199?** Check whether you run Nsasoft Nbmonitor at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A classic buffer overflow (CWE-120) exists in NBMonitor version 1.6.6.0 and potentially earlier versions within the registration key input field. The application fails to perform adequate bounds checking on the 'Key' field during the registration process. An attacker can trigger an application crash (Denial of Service) by supplying a payload of approximately 1,000 characters. While the attack requires local interaction to paste the string into the GUI, some CVSS mappings suggest a network vector if the registration process communicates externally; however, the primary exploit method is local user interaction. A public Proof of Concept (PoC) is available.

## Affected products

- Nsasoft (Nsauditor) NBMonitor 1.6.6.0 and earlier

## Timeline

- 2020-01-06: disclosed: Initial exploit PoC published on Exploit-DB
- 2026-02-11: advisory: CVE published/updated via VulnCheck and NVD

## References

- [http://www.nsauditor.com/](http://www.nsauditor.com/)
- [https://www.exploit-db.com/exploits/47866](https://www.exploit-db.com/exploits/47866)
- [https://www.vulncheck.com/advisories/nbmonitor-key-denial-of-service](https://www.vulncheck.com/advisories/nbmonitor-key-denial-of-service)

## Related threats

- [Nsauditor NBMonitor buffer overflow in registration code field](https://junglewise.ai/threats/cve-2021-47814-nsauditor-nbmonitor-buffer-overflow-in-registration-code-field)