Security readout for executives and security teams
Plain-English summary
This flaw affects COMMAX UMS Client ActiveX Control 1.7.0.2. A malicious input can corrupt memory in CNC_Ctrl.dll and may allow arbitrary code execution. The public record includes exploit references, but no source here confirms active exploitation. Organizations using this legacy control should treat exposure as urgent to verify.
Executive priority
High priority for environments using COMMAX UMS Client or legacy ActiveX workflows. The business risk is endpoint compromise through a vulnerable control, with public exploit references available. If the software is absent, priority drops after documented validation.
Technical view
CVE-2021-47705 is a CWE-787 heap-based buffer overflow in COMMAX UMS Client ActiveX Control 1.7.0.2. Excessively long string arrays passed through multiple functions in CNC_Ctrl.dll can cause heap corruption and potential code execution. CVSS v4.0 is 8.7: network attack vector, low complexity, no privileges, and user interaction required.
Likely exposure
Exposure is likely limited to systems with COMMAX UMS Client ActiveX Control version 1.7.0.2 installed or used. Because it is an ActiveX control, review Windows endpoints and legacy browser-dependent workflows. The source bundle does not identify other affected versions.
Exploitation context
Public exploit-related material is cited, including ExploitDB and Zero Science Lab. However, the source bundle does not show CISA KEV listing or any confirmed in-the-wild exploitation. User interaction is required according to the CVSS vector, reducing automation risk but not business impact.
Researcher notes
Evidence supports a heap overflow in CNC_Ctrl.dll tied to COMMAX UMS Client ActiveX Control 1.7.0.2. Public references include ExploitDB and Zero Science Lab. The provided sources do not name a vendor patch, affected version range beyond 1.7.0.2, or confirmed active exploitation.
Mitigation direction
- Inventory endpoints for COMMAX UMS Client ActiveX Control 1.7.0.2.
- Check COMMAX and trusted advisories for vendor-supported updates or replacement guidance.
- Remove or disable the control where it is not business-required.
- Restrict legacy browser and ActiveX use to tightly controlled systems.
- Prioritize compensating controls for users who must access COMMAX UMS workflows.
Validation and detection
- Confirm whether CNC_Ctrl.dll or the UMS ActiveX control is installed.
- Record installed version and compare against 1.7.0.2.
- Review software inventory and endpoint telemetry for COMMAX UMS Client usage.
- Check browser policies for ActiveX enablement on affected endpoints.
- Document any required business dependency before removal or isolation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-47705 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: 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
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-50232CVE reference · exploit
- Zero Science Lab Disclosure (ZSL-2021-5664)CVE reference · third-party-advisory
- ReferenceCVE reference · technical-description
- VulnCheck Advisory: CNC_Ctrl DllUnregisterServer Access ViolationCVE reference · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.