CVE-2007-3899 in Word
Summary
by MITRE
Unspecified vulnerability in Microsoft Word 2000 SP3, Word 2002 SP3, and Office 2004 for Mac allows user-assisted remote attackers to execute arbitrary code via a malformed string in a Word file, aka "Word Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 06/07/2025
The vulnerability identified as CVE-2007-3899 represents a critical memory corruption flaw affecting multiple versions of Microsoft Word including Word 2000 SP3, Word 2002 SP3, and Office 2004 for Mac. This weakness falls under the broader category of software vulnerabilities that can lead to arbitrary code execution, making it particularly dangerous for enterprise environments where Microsoft Office remains widely deployed. The vulnerability is classified as a user-assisted remote attack vector, meaning that successful exploitation requires some form of user interaction with a maliciously crafted document, typically through social engineering tactics that trick users into opening infected files. The memory corruption aspect indicates that the flaw involves improper handling of memory allocation and deallocation during processing of Word documents, potentially leading to buffer overflows or other memory-related issues that can be leveraged by attackers to gain control over affected systems.
The technical nature of this vulnerability stems from insufficient input validation within Microsoft Word's document parsing mechanisms, particularly when processing malformed strings within Word files. When a user opens a specially crafted document containing maliciously formatted strings, the application's memory management routines fail to properly handle the unexpected input, resulting in memory corruption that can be exploited to execute arbitrary code with the privileges of the user running the application. This type of vulnerability is categorized under CWE-125 as "Out-of-bounds Read" and potentially CWE-129 as "Improper Validation of Array Index," reflecting the fundamental issue with how the application processes array indices and memory boundaries when parsing document content. The attack typically involves creating a Word document with malformed string data that, when processed by the vulnerable software, causes memory corruption leading to code execution. The specific memory corruption patterns align with techniques described in the attack framework where attackers manipulate memory layout to achieve remote code execution, often leveraging the principle of stack-based buffer overflows or heap corruption vulnerabilities.
From an operational impact perspective, this vulnerability poses significant risks to organizations that continue to use legacy versions of Microsoft Office, as these systems remain exposed to exploitation despite being out of support. The user-assisted nature of the attack means that successful exploitation requires social engineering to convince users to open malicious documents, but once triggered, the consequences can be devastating. Attackers can leverage this vulnerability to gain unauthorized access to systems, potentially leading to data breaches, system compromise, or lateral movement within network environments. The vulnerability's impact extends beyond individual system compromise as it can serve as a vector for more sophisticated attacks, including privilege escalation and persistent access mechanisms. Organizations with outdated software versions are particularly vulnerable since these legacy systems lack modern security features and regular updates that would protect against such memory corruption exploits, making them attractive targets for threat actors seeking to exploit known weaknesses in older software environments.
The recommended mitigation strategies for CVE-2007-3899 focus on immediate remediation through software updates and patches, as Microsoft has released security updates addressing this vulnerability. Organizations should prioritize updating to supported versions of Microsoft Office, as the affected versions are no longer receiving security patches or support from Microsoft. Additionally, implementing administrative controls such as disabling automatic execution of macros and restricting user permissions when opening Office documents can significantly reduce the attack surface. Network-level protections including email filtering and sandboxing of document attachments can provide additional layers of defense against exploitation attempts. Security awareness training for end users remains critical to prevent successful social engineering attacks that rely on user interaction with malicious documents. The implementation of principle of least privilege access controls and regular security assessments can help identify and remediate other potential vulnerabilities in legacy systems that may be exploited in conjunction with this memory corruption flaw. Organizations should also consider implementing application whitelisting policies to prevent execution of untrusted Office documents and maintain comprehensive backup and recovery procedures to ensure business continuity in case of successful exploitation attempts.