CVE-2020-37199
Published: 11 February 2026
Summary
CVE-2020-37199 is a medium-severity Classic Buffer Overflow (CWE-120) vulnerability in Nsasoft Nbmonitor. Its CVSS base score is 4.6 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 2.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2020-37199 is a denial of service vulnerability in NBMonitor version 1.6.6.0, specifically affecting the registration key input field. The flaw, classified as CWE-120 (Buffer Copy without Checking Size of Input), allows attackers to crash the application by pasting a 1000-character buffer payload into the 'Key' field. It 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), indicating high impact on availability with no confidentiality or integrity effects.
Any unauthenticated attacker (PR:N) can exploit this vulnerability over the network (AV:N) with low attack complexity (AC:L) and no user interaction required (UI:N). Exploitation involves generating and submitting the oversized payload to the key field, resulting in an application crash and denial of service that disrupts NBMonitor's functionality.
Advisories and references, including a Vulncheck advisory on the NBMonitor key denial of service, an Exploit-DB proof-of-concept (ID 47866), and the NSAuditor website, document the issue but provide no specific details on patches or mitigations in the available CVE information.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2020-31189
Vulnerability details
NBMonitor 1.6.6.0 contains a denial of service vulnerability in its registration key input that allows attackers to crash the application. Attackers can generate a 1000-character buffer payload and paste it into the 'Key' field to trigger an application crash.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in local input field directly enables application crash via exploitation, matching Endpoint DoS by Application Exploitation.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requires validation of all input (including the registration key field) to enforce size limits and reject the 1000-character buffer that triggers the CWE-120 crash.
Implements memory protections that can block or contain buffer overflows in the key-input code path, limiting the DoS effect described in the CVE.
Provides denial-of-service protections that can throttle or isolate the availability impact once the oversized registration-key payload is submitted.