CVE-2021-47705

CNC_Ctrl DllUnregisterServer Access Violation

Published Dec 9, 2025 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Commax
Commax ums Client Activex Control
Vendors & Products Commax
Commax ums Client Activex Control
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title CNC_Ctrl DllUnregisterServer Access Violation
Weaknesses CWE-787
References
Metrics cvssV4_0

{'score': 8.7, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Apr 7, 2026, 2:05 PM
Reserved
Dec 5, 2025, 7:10 PM
Status
Deferred
Published
Dec 9, 2025, 9:15 PM
Modified
Jun 17, 2026, 4:18 AM