Microsoft Office MSCOMCTL.OCX Remote Code Execution Vulnerability (CVE-2012-1856)
Published In CISA KEV since Sources: CVE.org
What is affected, what to do
The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office 2003 SP3, Office 2003 Web Components SP3, Office 2007 SP2 and SP3, Office 2010 SP1, SQL Server 2000 SP4, SQL Server 2005 SP4, SQL Server 2008 SP2, SP3, R2, R2 SP1, and R2 SP2, Commerce Server 2002 SP4, Commerce Server 2007 SP2, Commerce Server 2009 Gold and R2, Host Integration Server 2004 SP1, Visual FoxPro 8.0 SP1, Visual FoxPro 9.0 SP2, and Visual Basic 6.0 Runtime allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption, aka "MSCOMCTL.OCX RCE Vulnerability."
The vulnerability is being actively exploited; treat it as a priority. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.
- Affected
- Microsoft Commerce Server
eq 2002..2002 - Microsoft Commerce Server
eq 2007..2007 - Microsoft Commerce Server
eq 2009..2009 - Microsoft Host Integration Server (HIS)
eq 2004..2004 - Microsoft Office
eq 2003..2003 - Microsoft Office
eq 2007..2007 - Microsoft Office
eq 2010..2010 - Microsoft SQL Server
eq 2000..2000 - Microsoft SQL Server
eq 2005..2005 - Microsoft SQL Server
eq 2008..2008 - Microsoft Visual Basic
eq 6.0..6.0 - Microsoft Visual FoxPro
eq 8.0..8.0 - Microsoft Visual FoxPro
eq 9.0..9.0
- Microsoft Commerce Server
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Metrics
8.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
8.8
CVSS v3
Severity High on the scale from 0 to 10.
Source: CVE.org
72.0 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.43
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 223.09 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- actively exploited
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 8.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 8.8
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 72.0 %
- High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 99.43
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- Actively exploited
- Published
In CISA KEV since
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- CISA assessment (SSVC)
- Exploitation: active · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 10 February 2025
Response and mitigation
Why act now?
Prioritisation rationale
This flaw is reachable over the network without authentication and only needs a user to open a crafted document or web page. Exploitation likelihood is very high: MSCOMCTL exploits have been a staple of RTF-based spear-phishing for years, though CISA does not flag known ransomware use. For organisations on current Microsoft 365 builds, residual risk is low. Exposure becomes serious wherever legacy software persists — Office 2003/2007, old SQL Server instances, or VB6/FoxPro line-of-business tools in OT and KRITIS environments. Record those systems as unsupported assets in the risk register and treat their migration or isolation as high priority.
Runbook step 1
Immediate response (0-24 h)
- Deploy the security update: Microsoft fixed this vulnerability in bulletin MS12-060 (August 2012). Look up the product-specific KB numbers in the vendor advisory and push them via WSUS/SCCM/Intune. Affected products include Office 2003/2007/2010, SQL Server 2000–2008 R2, Commerce Server, Host Integration Server 2004, Visual FoxPro and the VB6 Runtime.
- Inventory legacy assets: Identify every host running Office 2003/2007/2010, SQL Server 2000/2005/2008, or VB6/FoxPro applications. These products are end-of-life and receive no further updates. Also hunt for
MSCOMCTL.OCXinSystem32andSysWOW64and compare file versions against the advisory. Third-party VB6 software frequently ships its own copy of the file. - Set the kill bit for the TabStrip control: For CLSID
{1EFB6596-857C-11D1-B16A-00C0F0283628}(MSComctlLib.TabStrip), setCompatibility Flags = 0x400(DWORD) under bothHKLM\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\andHKLM\SOFTWARE\Microsoft\Office\Common\COM Compatibility\. Verify the CLSID against the advisory before rollout and enforce the setting via GPO. - Block inbound documents: Quarantine RTF and legacy binary Office formats (
.doc,.xls) from external senders at the mail gateway, or sanitise them through CDR. - Isolate unpatchable hosts: Remove Office 2003/2007 hosts that cannot be migrated from user networks and block mail and web browsing on them.
Runbook step 2
Mitigation layers
- Endpoint hardening (ASR): Enforce the Defender ASR rules "Block Office applications from creating child processes" (
D4F940AB-401B-4EFC-AADC-AD5F3C50688A) and "Block Office applications from injecting code into other processes" in block mode. - Configuration change: Use Office GPOs to disable all ActiveX controls in documents. Enable File Block for RTF and Office 2003 binary formats, and force Protected View for files originating from the internet.
- Browser layer: Retire Internet Explorer, or restrict Edge IE mode to an explicit site list. Prohibit ActiveX execution in the Internet zone via GPO.
- Network segmentation: Move legacy hosts into dedicated VLANs. These are often HMI or engineering workstations running VB6 tooling in OT environments. Allow outbound HTTP/HTTPS only through an allowlisting proxy.
- IPS/mail filtering: Enable signatures that flag RTF files containing
\objdatawith an embeddedMSComctlLib.TabStripobject. The common ET and Snort rulesets ship MSCOMCTL exploit patterns. - Least privilege: Remove local admin rights from users so that successful code execution stays confined to a standard user context.
- Endpoint hardening (ASR): Enforce the Defender ASR rules "Block Office applications from creating child processes" (
Runbook step 3
Detection rules
- Sysmon EID 1 / Windows 4688: Office spawning a shell or script host. KQL:
DeviceProcessEvents | where InitiatingProcessFileName in~ ("winword.exe","excel.exe") and FileName in~ ("cmd.exe","powershell.exe","mshta.exe","rundll32.exe") - Sysmon EID 7 (image load): WINWORD.EXE or EXCEL.EXE loading
MSCOMCTL.OCXwhen a document is opened from Downloads or Temp paths. This is rare in modern estates and worth investigating. - Sysmon EID 11 (file create): Office processes dropping
.exe,.dllor.scrfiles into%TEMP%,%APPDATA%orC:\ProgramData. This is a classic dropper pattern. - YARA/mail scanning: RTF files (
{\rtf) that contain\objocxor\objdatatogether with the hex-encoded TabStrip CLSID or the stringMSComctlLib.TabStrip. - Network telemetry (Zeek/proxy): Office processes or their children making HTTP connections to rare domains shortly after an attachment is opened (
http.log, anomalous user agents).
- Sysmon EID 1 / Windows 4688: Office spawning a shell or script host. KQL:
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office 2003 SP3, Office 2003 Web Components SP3, Office 2007 SP2 and SP3, Office 2010 SP1, SQL Server 2000 SP4, SQL Server 2005 SP4, SQL Server 2008 SP2, SP3, R2, R2 SP1, and R2 SP2, Commerce Server 2002 SP4, Commerce Server 2007 SP2, Commerce Server 2009 Gold and R2, Host Integration Server 2004 SP1, Visual FoxPro 8.0 SP1, Visual FoxPro 9.0 SP2, and Visual Basic 6.0 Runtime allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption, aka "MSCOMCTL.OCX RCE Vulnerability."
Source: NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| microsoft | commerce_server |
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| microsoft | host_integration_server |
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| microsoft | office |
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| microsoft | office_web_components |
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| microsoft | sql_server |
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| microsoft | visual_basic |
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| microsoft | visual_foxpro |
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Vendors and products
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| CISA KEV Catalog | CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov | actively exploited |
References & sources
- docs.microsoft.comMS12-060Vendor advisory, x_refsource_MS, Patch, Vendor advisory
- oval.cisecurity.orgoval:org.mitre.oval:def:15447Vulnerability database, signature, x_refsource_OVAL, Broken link
- us-cert.govTA12-227AThird-party advisory, x_refsource_CERT, Third-party advisory, US government resource
- securityfocus.com54948Vulnerability database, x_refsource_BID, Broken link, Third-party advisory, Vulnerability database
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2012-1856government-resource, US government resource
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<a href="https://intel.neosec.eu/en/cve/CVE-2012-1856"><img src="https://intel.neosec.eu/badge/cve/CVE-2012-1856.svg?lang=en" alt="CVE-2012-1856 – NEOSEC Intel" height="20"></a>