CVE-2010-1901 in Office Compatibility Pack
Summary
by MITRE
Microsoft Office Word 2002 SP3, 2003 SP3, and 2007 SP2; Microsoft Office 2004 and 2008 for Mac; Open XML File Format Converter for Mac; Office Word Viewer; and Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP2 do not properly handle unspecified properties in rich text data, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted RTF document, aka "Word RTF Parsing Engine Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 09/22/2021
This vulnerability resides in the Microsoft Office Word processing engine's handling of rich text format documents, specifically within the RTF parsing functionality that has been present since Office 2002 through 2007. The flaw manifests when the application encounters unspecified properties within rich text data structures during document parsing operations. This represents a classic memory corruption vulnerability that falls under the CWE-125 weakness category, which describes out-of-bounds read conditions that can lead to arbitrary code execution. The vulnerability affects multiple versions across different Office platforms including Windows and Mac operating systems, indicating a widespread impact across Microsoft's Office suite. The attack vector involves remote exploitation through crafted RTF documents that contain malformed property values, which when processed by Word's RTF parser trigger memory corruption conditions.
The technical implementation of this vulnerability stems from inadequate input validation within the RTF parsing engine component of Microsoft Office applications. When Word encounters rich text documents containing unexpected or malformed property specifications, the parser fails to properly validate these elements before attempting to process them in memory. This processing failure results in memory corruption that can be leveraged by attackers to execute arbitrary code with the privileges of the user running the affected Office application. The vulnerability demonstrates characteristics consistent with the ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code. The memory corruption occurs during the document parsing phase when the application attempts to allocate or access memory regions that have not been properly initialized or validated.
The operational impact of this vulnerability extends across multiple Microsoft Office products and platforms, making it particularly dangerous for enterprise environments where Office documents are frequently shared and opened. Attackers can craft malicious RTF documents that, when opened by an affected Office application, will trigger the memory corruption and potentially allow remote code execution. This creates a significant risk for organizations where users may inadvertently open compromised documents received via email or other file sharing mechanisms. The vulnerability is especially concerning because it affects both the Windows and Mac versions of Office, as well as various compatibility packs and viewers that handle RTF format files. Organizations with legacy Office installations are particularly vulnerable, as these older versions may not have received the necessary security updates or patches that would address this specific parsing engine flaw.
Mitigation strategies for this vulnerability should focus on multiple defensive layers including immediate patch deployment for all affected Office versions, network-based filtering of RTF documents, and user education about the risks of opening untrusted documents. The recommended approach involves applying Microsoft security patches that address the RTF parsing engine memory corruption issues, while also implementing content filtering solutions that can detect and block suspicious RTF document structures. Organizations should also consider disabling RTF document handling in Office applications where possible, particularly in high-risk environments. The vulnerability's classification as a memory corruption issue means that traditional antivirus solutions may not detect the malicious documents, necessitating more sophisticated content inspection and sandboxing approaches. Network administrators should implement email filtering rules that block RTF attachments from untrusted sources and consider deploying endpoint protection solutions that can monitor for suspicious memory access patterns during document processing operations.