CVE-2010-1903 in Word
Summary
by MITRE
Microsoft Office Word 2002 SP3 and 2003 SP3, and Office Word Viewer, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a malformed record in a Word file, aka "Word HTML Linked Objects Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 09/22/2021
The vulnerability identified as CVE-2010-1903 represents a critical memory corruption flaw within Microsoft Office Word 2002 SP3, Word 2003 SP3, and Office Word Viewer applications. This vulnerability specifically targets the handling of HTML linked objects within Word documents, creating a dangerous condition where malformed records can trigger unpredictable behavior in the application's memory management systems. The flaw exists in the way these Microsoft Office applications process certain structured data elements that are embedded within Word documents, particularly when these elements contain irregular or malformed data structures that exceed expected boundaries.
The technical exploitation of this vulnerability occurs through the manipulation of HTML linked objects within Word documents, which are typically used to embed external content or references within documents. When a user opens a maliciously crafted Word file containing malformed records, the Office application attempts to parse these HTML linked objects and encounters unexpected data patterns that cause memory corruption. This memory corruption can manifest in two primary ways: either through arbitrary code execution that allows attackers to run malicious software with the privileges of the victim user, or through denial of service conditions that cause the application to crash or become unresponsive. The vulnerability stems from inadequate input validation and boundary checking mechanisms within the document parsing code, particularly in the handling of complex data structures that are part of the HTML linked objects functionality.
The operational impact of this vulnerability extends beyond simple application instability, as it provides attackers with a potential pathway for more sophisticated attacks within enterprise environments. When exploited successfully, the vulnerability can enable attackers to execute arbitrary code on vulnerable systems, potentially leading to complete system compromise. The attack vector is particularly concerning because it can be delivered through seemingly legitimate Word documents that users might receive via email attachments, web downloads, or shared network locations. The vulnerability affects multiple versions of Microsoft Office, making it a widespread concern across organizations that have not yet deployed appropriate patches. Organizations running these older versions of Office are particularly at risk as the memory corruption can be triggered simply by opening a malicious document, requiring no additional user interaction beyond normal document opening procedures.
Microsoft has addressed this vulnerability through security updates that include enhanced input validation and boundary checking mechanisms for HTML linked object processing within Word documents. The recommended mitigation strategy involves immediate deployment of the applicable security patches released by Microsoft, along with implementing additional security measures such as email filtering and document validation procedures. Organizations should also consider implementing application whitelisting policies to restrict execution of Office applications from untrusted sources, and establish regular security awareness training programs to educate users about the risks of opening suspicious document attachments. From a cybersecurity perspective, this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and can be categorized under ATT&CK technique T1203 for legitimate program execution. The vulnerability demonstrates the importance of proper input validation and memory safety practices in preventing remote code execution through document processing applications.