CVE-2021-47705

8.7 highEPSS 0.5%

High (8.7). EPSS 0.5% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

8.7 high

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

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-11-01)
CWE: CWE-787
Published: 2025-12-09
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

References

https://www.commax.com
https://www.exploit-db.com/exploits/50232
https://www.vulncheck.com/advisories/commax-ums-client-activex-control-cnc-ctrl-dll-heap-buffer-overflow
https://www.zeroscience.mk/en/vulnerabilities/ZSL-2021-5664.php

Check your stack JSON