CVE-2014-6356 in Word
Summary
by MITRE
Array index error in Microsoft Word 2007 SP3, Word 2010 SP2, and Office Compatibility Pack SP3 allows remote attackers to execute arbitrary code via a crafted Office document, aka "Invalid Index Remote Code Execution Vulnerability."
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Analysis
by VulDB Data Team • 03/01/2022
The vulnerability identified as CVE-2014-6356 represents a critical array index error within Microsoft Word 2007 SP3, Word 2010 SP2, and the Office Compatibility Pack SP3 applications. This flaw exists in the way these Microsoft Office products handle certain Office document formats, specifically when processing malformed or crafted documents that contain invalid array indices. The vulnerability falls under the category of memory corruption issues that can lead to arbitrary code execution, making it particularly dangerous for enterprise environments where Office documents are frequently shared and opened.
The technical implementation of this vulnerability stems from insufficient bounds checking during the processing of Office document structures. When Microsoft Word encounters a crafted document containing maliciously constructed array indices, the application fails to properly validate these indices before accessing memory locations. This improper validation allows attackers to manipulate memory access patterns and potentially overwrite critical memory areas with malicious code. The flaw is classified as a buffer over-read condition according to CWE-125, where an application reads data past the end of a buffer, and can be categorized under the broader ATT&CK technique T1059.007 for command and scripting interpreter usage, as successful exploitation typically involves executing malicious code through the compromised application.
The operational impact of CVE-2014-6356 extends beyond simple remote code execution, as it provides attackers with a pathway to establish persistent access within target environments. An attacker who successfully exploits this vulnerability can gain full control over the affected system, potentially leading to data exfiltration, privilege escalation, or use of the compromised machine as a launch point for further attacks within the network. The vulnerability is particularly concerning because it affects multiple versions of Microsoft Office, including older service pack releases that may still be in use within organizations that have not yet deployed updated patches. This widespread affected scope increases the attack surface and makes the vulnerability attractive to both nation-state actors and cybercriminals seeking to exploit legacy systems.
Mitigation strategies for CVE-2014-6356 require immediate action from organizations to apply Microsoft security updates and patches that address the underlying array index validation issues. System administrators should prioritize deployment of the relevant Microsoft Security Bulletins and ensure that all Office installations are updated to versions that contain the necessary fixes. Additionally, organizations should implement defensive measures such as email filtering to block suspicious Office documents, disable macro execution in Office applications, and employ application whitelisting policies to prevent unauthorized code execution. Network segmentation and monitoring can help detect potential exploitation attempts, while regular security assessments should verify that systems remain patched against this vulnerability. The remediation process should also include user education to avoid opening suspicious documents and to recognize social engineering attempts that might deliver malicious Office files.