CVE-2012-1856
Microsoft Office MSCOMCTL.OCX Remote Code Execution Vulnerability
Description
CVE-2012-1856 is a HIGH vulnerability in Microsoft Office, carrying a CVSS 3.1 score of 8.8. The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption. A typical exploitation scenario involves an attacker distributing a specially crafted Office document via email or file-sharing, with code execution occurring when the victim opens the malicious document. This CVE is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog with a remediation deadline of 2022-03-24. With an EPSS score of 0.91946 (99.69th percentile), this vulnerability exhibits substantial real-world exploitation activity.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | commerce server | 2002; 2007; 2009 |
| microsoft | host integration server | 2004 |
| microsoft | office | 2003; 2007; 2010 |
| microsoft | office web components | 2003 |
| microsoft | sql server | 2000; 2005; 2008 |
| microsoft | visual basic | 6.0 |
| microsoft | visual foxpro | 8.0; 9.0 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- http://www.securityfocus.com/bid/54948(Broken Link, Third Party Advisory, VDB Entry)
- http://www.us-cert.gov/cas/techalerts/TA12-227A.html(Third Party Advisory, US Government Resource)
- https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-060(Patch, Vendor Advisory)
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15447(Broken Link)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2012-1856(US Government Resource)
Weakness Type
Vulnerability Classification
At the time of analysis, no specific CWE classification has been formally assigned to CVE-2012-1856. The vulnerability in Microsoft Office involves a flaw that allows attackers to compromise affected systems. The vulnerability exists in a Windows Common Control used by Microsoft Office applications. An ActiveX control improperly handles certain memory operations, allowing an attacker to trigger an exploitable condition through a specially crafted document or web page. The memory corruption allows for arbitrary code execution in the context of the current user, with potential for privilege escalation through additional attack chains. Despite the absence of a formal CWE designation, the vulnerability's inclusion in the CISA KEV catalog and its CVSS score of 8.8 confirm that it poses a serious, actively exploited threat.
The HIGH severity rating indicates that successful exploitation has substantial consequences for affected organizations. Given the widespread deployment of Microsoft Office, this vulnerability represents a significant attack surface that demands immediate attention regardless of formal weakness classification.
Impact Analysis
CVE-2012-1856 carries a CVSS 3.1 score of 8.8 (HIGH) with the following impact characteristics.
Confidentiality (HIGH): An attacker who successfully exploits this vulnerability gains access to all data accessible by the affected component. In the context of Microsoft Office, this can include sensitive configuration data, user credentials, proprietary business information, and any data the application processes or stores.
Integrity (HIGH): Successful exploitation enables an attacker to modify, corrupt, or destroy data within the affected system. This includes the potential to tamper with system files, install backdoors or persistent malware, alter critical configurations, and manipulate application logic to serve malicious purposes.
Availability (HIGH): The vulnerability can be exploited to cause complete denial of service, rendering the affected system or application unavailable to legitimate users. System crashes, infinite loops, or resource exhaustion may persist until manual administrative intervention restores normal operation.
Scope (Unchanged): The exploitation impact is contained within the security scope of the vulnerable component itself. While the damage within that scope can be severe with full compromise of the affected application, lateral impact on other systems requires additional exploitation steps.
With an EPSS score of 0.91946 (99.69th percentile), this vulnerability ranks among the most likely to be exploited in the wild, placing it well above the vast majority of all cataloged vulnerabilities in terms of real-world exploitation activity.
Exploit Maturity
CVE-2012-1856 demonstrates significant exploit maturity with confirmed active exploitation in the wild.
Active exploitation: This vulnerability is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming that it has been observed being actively exploited by threat actors. The KEV designation mandates federal agencies to apply remediation within a defined timeframe and serves as a strong signal of real-world risk.
Ransomware association: As of the current KEV catalog data, no direct ransomware association has been confirmed for CVE-2012-1856. However, the vulnerability's characteristics and confirmed exploitation in the wild mean it remains a viable vector for various threat actors including cybercriminals and advanced persistent threat groups.
Exploit availability: While specific public exploit code references were not identified in the NVD data, the vulnerability's inclusion in the KEV catalog confirms real-world exploitation. Threat intelligence sources and underground forums may host exploit tools not captured in public databases.
KEV remediation deadline: CISA set a remediation deadline of 2022-03-24 for federal agencies, underscoring the urgency of patching. Organizations beyond the federal sector should treat this deadline as a strong indicator of the risk level and prioritize remediation accordingly.
Remediation
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Apply vendor-provided security patches immediately. Apply updates per vendor instructions. Consult the official security advisory for specific patch versions and deployment guidance.
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Verify affected product versions in your environment. Affected products include: Commerce Server (2002; 2007; 2009), Host Integration Server (2004), Office (2003; 2007; 2010), Office Web Components (2003), Sql Server (2000; 2005; 2008), Visual Basic (6.0), Visual Foxpro (8.0; 9.0). Conduct an inventory of all instances across your organization to ensure comprehensive patch coverage and prevent any unpatched systems from remaining exposed.
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Implement interim mitigations if immediate patching is not feasible. Restrict network access to the affected service using firewall rules and access control lists. Limit exposure to trusted networks only and monitor for suspicious network traffic patterns targeting the vulnerable service.
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Enable enhanced monitoring and detection. Configure intrusion detection systems and endpoint detection and response (EDR) tools to detect exploitation attempts targeting CVE-2012-1856. Review security logs for indicators of compromise and establish alerting for anomalous behavior on systems running affected software.
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Conduct a post-patch vulnerability assessment. After applying patches, verify that the remediation was effective by running vulnerability scans against all previously affected systems. Confirm the vulnerability is no longer present and ensure no instances were missed during deployment.
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Review and update incident response procedures. Ensure your incident response plan accounts for potential exploitation of CVE-2012-1856. Document patching status and maintain evidence of remediation for compliance and audit purposes.
Technical Details
CVE-2012-1856 is a high-severity vulnerability affecting Microsoft Office. The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption.
Attack Vector: The attack vector is NETWORK, meaning the vulnerability can be exploited remotely over the network without requiring the attacker to have local access to the target system. This significantly expands the potential attacker population and makes the vulnerability accessible to remote threat actors.
Attack Complexity: The attack complexity is LOW. Exploitation does not require specialized conditions, race conditions, or extensive preparation — making it accessible to a broad range of attackers including those with limited technical sophistication.
Prerequisites: No prior privileges are required. User interaction is required, typically involving a victim opening a specially crafted file, clicking a malicious link, or visiting a compromised website.
Underlying mechanism: The vulnerability exists in a Windows Common Control used by Microsoft Office applications. An ActiveX control improperly handles certain memory operations, allowing an attacker to trigger an exploitable condition through a specially crafted document or web page. The memory corruption allows for arbitrary code execution in the context of the current user, with potential for privilege escalation through additional attack chains.
Affected products: Commerce Server (2002; 2007; 2009), Host Integration Server (2004), Office (2003; 2007; 2010), Office Web Components (2003), Sql Server (2000; 2005; 2008), Visual Basic (6.0), Visual Foxpro (8.0; 9.0). Organizations should cross-reference their deployed versions against this list to assess their exposure to this vulnerability.
Frequently Asked Questions
What is CVE-2012-1856?
CVE-2012-1856 is a high-severity vulnerability (CVSS 8.8) affecting Microsoft Office. The TabStrip ActiveX control in the Common Controls in MSCOMCTL.OCX in Microsoft Office allows remote attackers to execute arbitrary code via a crafted (1) document or (2) web page that triggers system-state corruption. It is listed in CISA's Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild.
Which products are affected by CVE-2012-1856?
The vulnerability affects Microsoft products including Commerce Server, Host Integration Server, Office, Office Web Components, Sql Server, Visual Basic, Visual Foxpro. Affected versions include 2002; 2007; 2009. Organizations should consult the vendor's security advisory for the complete list of affected versions and available patches.
How do I fix CVE-2012-1856?
Apply updates per vendor instructions. Refer to the official vendor security advisory for specific patch downloads and deployment instructions. If immediate patching is not possible, implement interim mitigations such as restricting access to the vulnerable component, enabling enhanced monitoring, and educating users about potential attack vectors. Verify remediation effectiveness with post-patch vulnerability scanning.
How severe is CVE-2012-1856?
CVE-2012-1856 is rated HIGH with a CVSS 3.1 score of 8.8. Its EPSS score of 0.91946 places it in the 99.69th percentile for exploitation likelihood, meaning it is more likely to be exploited than 99.7% of all known vulnerabilities. The KEV remediation deadline was 2022-03-24, and the vulnerability's confirmed active exploitation makes it a high-priority remediation target. Organizations should treat patching as urgent regardless of whether they believe they are currently targeted.
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