Cyber Posture

CVE-2021-47814

HighPublic PoC

Published: 16 January 2026

Published
16 January 2026
Modified
29 January 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0002 4.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-47814 is a high-severity Classic Buffer Overflow (CWE-120) vulnerability in Nsasoft Nbmonitor. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 4.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

NVD Description

NBMonitor 1.6.8 contains a denial of service vulnerability that allows attackers to crash the application by overflowing the registration code input field. Attackers can paste a 256-character buffer into the registration key field to trigger an application crash and potential…

more

system instability.

Deeper analysisAI

CVE-2021-47814 is a denial-of-service vulnerability in NBMonitor version 1.6.8, stemming from a buffer overflow in the registration code input field, classified as CWE-120. Attackers can trigger an application crash and potential system instability by pasting a 256-character buffer into the registration key field. The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), highlighting its high availability impact.

The vulnerability enables remote exploitation over the network with low complexity, requiring no authentication privileges or user interaction. Unauthenticated attackers can achieve a crash of the NBMonitor application, disrupting its functionality and potentially causing broader system instability.

References include advisories and proof-of-concept exploits, such as Exploit-DB entry 49964 and a VulnCheck advisory on the NBMonitor denial-of-service PoC, along with details from nsauditor.com. No specific patches or mitigation steps are outlined in the provided references.

Details

CWE(s)

Affected Products

nsasoft
nbmonitor
1.6.8

CVEs Like This One

CVE-2020-37199Same product: Nsasoft Nbmonitor
CVE-2020-37207Same vendor: Nsasoft
CVE-2020-37130Same vendor: Nsasoft
CVE-2020-37212Same vendor: Nsasoft
CVE-2020-37201Same vendor: Nsasoft
CVE-2020-37206Same vendor: Nsasoft
CVE-2020-37211Same vendor: Nsasoft
CVE-2020-37196Same vendor: Nsasoft
CVE-2021-47815Same vendor: Nsasoft
CVE-2020-37204Same vendor: Nsasoft

References