Remote Code Execution in Microsoft Office MSCOMCTL.OCX (CVE-2012-1856) Threatens Documents and Web Content
What It Is — The TabStrip ActiveX control in MSCOMCTL.OCX, shipped with Microsoft Office, contains a remote‑code‑execution flaw. An attacker can deliver a crafted Office document or embed malicious code in a web page to corrupt system state and run arbitrary code.
Exploitability — Publicly disclosed; proof‑of‑concept code exists. CVSS v3.1 base score 7.5 (High). No widespread active‑exploitation reports, but the vulnerability is trivially weaponizable.
Affected Products — Microsoft Office (all versions that include MSCOMCTL.OCX, e.g., Office 2007‑2019) on Windows platforms.
Why It Matters for Trust & Control Assurance
- Demonstrates the need for continuous patch‑management controls and evidence of timely remediation.
- Highlights the importance of application‑allowlist and ActiveX hardening as part of a defensible audit trail.
- Enterprise buyers increasingly require proof that legacy components are either patched or mitigated, a core control across multiple frameworks (e.g., NIST CSF 2.0 “Protect” function).
Recommended Actions
- Deploy Microsoft’s security update that removes or updates MSCOMCTL.OCX.
- If immediate patching is not possible, disable the TabStrip ActiveX control via Group Policy or registry.
- Verify remediation through automated configuration monitoring and retain evidence for audit readiness.
Source: CISA KEV – CVE‑2012‑1856