CVE-2015-1649 in Office
Summary
by MITRE
Use-after-free vulnerability in Microsoft Word 2007 SP3, Office 2010 SP2, Word 2010 SP2, Word Viewer, Office Compatibility Pack SP3, Word Automation Services on SharePoint Server 2010 SP2, and Office Web Apps Server 2010 SP2 allows remote attackers to execute arbitrary code via a crafted Office document, aka "Microsoft Office Component Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 05/06/2022
This vulnerability represents a critical use-after-free flaw in Microsoft Office components that affects multiple versions including Word 2007 SP3, Office 2010 SP2, and various supporting applications. The vulnerability stems from improper memory management where a freed memory block is still accessed after the memory has been released, creating a scenario where malicious code can manipulate the freed memory location. The flaw specifically impacts the Microsoft Office Component and occurs when processing maliciously crafted Office documents that trigger the vulnerable code path. This type of vulnerability falls under the CWE-416 category, which specifically addresses use-after-free conditions that can lead to arbitrary code execution. The attack vector requires remote exploitation through a specially crafted Office document, making it particularly dangerous for enterprise environments where users frequently open documents from external sources or web-based applications.
The operational impact of this vulnerability extends beyond simple code execution to potentially enable full system compromise when exploited successfully. Attackers can leverage this weakness to gain arbitrary code execution privileges, potentially allowing them to install malware, modify system files, or establish persistent backdoors. The vulnerability affects both desktop and server versions of Microsoft Office applications, including Word Automation Services on SharePoint Server 2010 SP2 and Office Web Apps Server 2010 SP2, which means that organizations with web-based document processing capabilities face additional exposure. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1078 (Valid Accounts) as attackers can use the executed code to escalate privileges or move laterally within the network. The remote exploitation capability makes this vulnerability particularly attractive to threat actors who can deploy malicious documents through phishing campaigns, web compromises, or other remote delivery mechanisms.
Mitigation strategies should focus on immediate patch management and network-based protections to address this vulnerability effectively. Microsoft released security updates that resolve the use-after-free condition by correcting the memory management logic in the affected Office components. Organizations should prioritize deploying these patches across all affected systems including desktop applications, SharePoint servers, and Office Web Apps environments. Network segmentation and email filtering solutions can provide additional defense-in-depth measures by blocking suspicious Office document attachments before they reach end users. Security monitoring should include detection of anomalous Office process behavior and memory access patterns that might indicate exploitation attempts. The vulnerability also highlights the importance of user education and awareness programs to reduce the likelihood of successful social engineering attacks that deliver malicious documents. Implementing application whitelisting policies and disabling unnecessary Office automation features can further reduce the attack surface, while regular security assessments should verify that all affected systems have been properly updated and remain protected against similar memory corruption vulnerabilities.