Vulnerability · Published Dec 9, 2025 · Assigned by VulnCheck
CVE-2021-47719CNC_Ctrl DllUnregisterServer f5501 Access Violation
High 8.7
In plain English
A high-severity out-of-bounds write in COMMAX WebViewer ActiveX Control from COMMAX Co., Ltd.. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).
Official description
COMMAX WebViewer ActiveX Control 2.1.4.5 contains a buffer overflow vulnerability that allows attackers to execute arbitrary code by providing excessively long string arrays through multiple functions. Attackers can exploit boundary errors in Commax_WebViewer.ocx to cause buffer overflow conditions and potentially gain code execution.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| COMMAX Co., Ltd. | COMMAX WebViewer ActiveX Control | 2.1.4.5 |
Weakness: CWE-787 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References
- ExploitDB-50231 exploit
- Zero Science Lab Disclosure (ZSL-2021-5663) third-party-advisory
- Reference product
- VulnCheck Advisory: CNC_Ctrl DllUnregisterServer f5501 Access Violation third-party-advisory