CVE-2016-3281 in Office
Summary
by MITRE
Microsoft Office 2010 SP2, Word 2010 SP2, Word 2013 SP1, Word 2013 RT SP1, Word 2016, Word for Mac 2011, Word 2016 for Mac, Word Automation Services on SharePoint Server 2010 SP2, and Office Web Apps 2010 SP2 allow remote attackers to execute arbitrary code via a crafted Office document, aka "Microsoft Office Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 09/01/2022
This vulnerability represents a critical memory corruption flaw in Microsoft Office applications that affects multiple versions including Office 2010 SP2, Word 2010 SP2, Word 2013 SP1, Word 2013 RT SP1, Word 2016, Word for Mac 2011, Word 2016 for Mac, and Office Web Apps 2010 SP2. The vulnerability stems from improper handling of malformed Office documents during the parsing process, creating opportunities for remote code execution attacks. According to CWE-125, this vulnerability falls under the category of "Out-of-bounds Read" where the application fails to properly validate input data structures, leading to memory corruption that can be exploited by malicious actors. The flaw specifically impacts the document parsing engine within Microsoft Office applications, particularly when processing specially crafted Office files that contain malformed data structures.
The technical exploitation of this vulnerability occurs when a user opens or previews a maliciously crafted Office document, triggering a memory corruption condition that allows attackers to execute arbitrary code with the privileges of the affected user. This attack vector leverages the principle of privilege escalation through memory corruption, where attackers can manipulate memory pointers and buffer boundaries to redirect program execution flow. The vulnerability is particularly dangerous because it can be triggered through various attack vectors including email attachments, web downloads, and document previews in web applications, making it a prime target for phishing campaigns and targeted attacks. The attack technique aligns with ATT&CK methodology under T1203 - Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code on target systems.
The operational impact of this vulnerability extends beyond individual user compromise to affect enterprise environments where Office applications are widely deployed. Organizations face significant risks including data exfiltration, persistent backdoor installation, and lateral movement within networks once initial compromise occurs. The vulnerability affects both desktop and web-based Office deployments, creating multiple attack surfaces for threat actors. Security teams must consider the widespread deployment of affected Office versions across enterprise environments, where legacy systems may not receive timely updates. The memory corruption nature of the vulnerability means that even sandboxed environments may be compromised, as the corruption can occur at the application level rather than requiring system-level privileges. This makes the vulnerability particularly concerning for organizations with strict security controls, as it can bypass traditional security boundaries.
Mitigation strategies should prioritize immediate patching of affected Office versions, with particular attention to the specific versions mentioned in the vulnerability description. Organizations should implement comprehensive email filtering and document validation procedures to prevent malicious Office documents from reaching end users. Network-based protections including web application firewalls and content inspection systems can help detect and block malicious Office documents during transit. The implementation of principle of least privilege and user education programs can reduce the impact of successful exploitation attempts. Security monitoring should focus on unusual process execution patterns and memory access anomalies that may indicate exploitation attempts. Regular vulnerability assessments and penetration testing should verify that patch management processes are effectively addressing this and similar memory corruption vulnerabilities. The remediation approach should also consider implementing application whitelisting policies to prevent execution of unauthorized Office document handlers and ensure that only trusted Office applications can process documents.