CNC_Ctrl DllUnregisterServer Access Violation
Priority LOW 38CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
COMMAX UMS Client ActiveX Control 1.7.0.2 contains a heap-based buffer overflow vulnerability that allows attackers to execute arbitrary code by providing excessively long string arrays through multiple functions. Attackers can exploit improper boundary validation in CNC_Ctrl.dll to cause heap corruption and potentially gain system-level access.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00486 42nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| COMMAX Co., Ltd. | COMMAX UMS Client ActiveX Control | 1.7.0.2 | — | No fix listed | CNA |
- COMMAX UMS Client ActiveX Control VendorCOMMAX Co., Ltd. Affected 1.7.0.2 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47705
- 2026-10-03 Alias added: GHSA-hx89-cwv8-4xch
References
More COMMAX Co., Ltd. vulnerabilities
- TI-2021-22325 COMMAX Smart Home IoT Control System SQL Injection Authentication Bypass CVSS 4.0CRITICAL 9.3
- TI-2021-22336 CNC_Ctrl DllUnregisterServer f5501 Access Violation CVSS 4.0HIGH 8.7
- TI-2021-22324 COMMAX CVD-Axx DVR Weak Default Credentials Stream Disclosure CVSS 4.0CRITICAL 9.3
- TI-2021-22326 COMMAX Smart Home Ruvie CCTV Bridge DVR Service Config Write / DoS CVSS 4.0HIGH 8.7
- TI-2021-22360 COMMAX Biometric Access Control System 1.0.0 Reflected XSS via Cookie Parameters CVSS 4.0MEDIUM 5.1
- TI-2019-13818 Commax WallPad Remote Code Execution Vulnerability CVSS 3.1HIGH 8.8
Sources
- CVE-2021-47705 · CVE Program
- CVE-2021-47705 · NVD
- FIRST EPSS
- GHSA-hx89-cwv8-4xch · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences