CVE-2016-7244 in Office
Summary
by MITRE
Microsoft Office 2007 SP3 allows remote attackers to cause a denial of service (application hang) via a crafted Office document, aka "Microsoft Office Denial of Service Vulnerability."
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Analysis
by VulDB Data Team • 09/30/2022
The vulnerability identified as CVE-2016-7244 represents a significant denial of service weakness in Microsoft Office 2007 Service Pack 3 that enables remote attackers to disrupt normal application operations through carefully constructed malicious documents. This flaw specifically targets the document parsing mechanisms within Office 2007, creating a scenario where legitimate user interactions with compromised files result in application hangs rather than proper document rendering or processing. The vulnerability exploits inherent weaknesses in how Office handles certain malformed or specially crafted document structures, particularly affecting the application's ability to process and display content without crashing or becoming unresponsive. This type of vulnerability falls under the broader category of software reliability issues that can be weaponized for operational disruption.
The technical implementation of this vulnerability involves the manipulation of specific document format elements that trigger infinite loops or excessive resource consumption within the Office application's parsing engine. When a user opens a specially crafted Office document, the application's internal processing routines encounter unexpected data structures that cause the software to enter a state where it continuously processes the malicious content without proper termination conditions. This results in the application becoming unresponsive and requiring manual intervention to restore normal functionality. The flaw demonstrates poor input validation and error handling within the document processing pipeline, allowing attackers to craft documents that exploit these weaknesses through carefully constructed payload elements.
From an operational perspective, this vulnerability poses substantial risks to enterprise environments where Office 2007 is widely deployed, particularly in scenarios where users frequently open documents from external sources or email attachments. The denial of service condition can effectively prevent productivity and may require system administrators to implement immediate workarounds or temporary application restrictions. Organizations relying on Office 2007 for critical business operations could experience significant downtime and reduced operational capacity when this vulnerability is exploited. The attack vector is particularly concerning because it requires minimal technical expertise to construct malicious documents that can affect users across different system configurations and security levels.
The vulnerability aligns with CWE-400, which categorizes improper handling of input data leading to resource exhaustion or application instability, and demonstrates characteristics consistent with ATT&CK technique T1499.004 related to network denial of service attacks. Mitigation strategies should include immediate deployment of Microsoft security patches, implementation of document validation policies, and user education regarding suspicious file attachments. Organizations should also consider network-level controls to restrict access to potentially malicious document formats and implement application whitelisting to prevent execution of untrusted Office documents. Additionally, regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable versions of Office that require immediate remediation. The broader implications highlight the importance of maintaining current software versions and implementing comprehensive security controls to protect against similar vulnerabilities in legacy applications.