CVE-2010-3217 in Word
Summary
by MITRE
Double free vulnerability in Microsoft Word 2002 SP3 allows remote attackers to execute arbitrary code via a Word document with crafted List Format Override (LFO) records, aka "Word Pointer Vulnerability."
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Analysis
by VulDB Data Team • 09/26/2021
The CVE-2010-3217 vulnerability represents a critical double free memory corruption issue affecting Microsoft Word 2002 Service Pack 3, which has significant implications for enterprise security environments. This vulnerability specifically targets the handling of List Format Override (LFO) records within Word documents, creating a condition where memory allocated to process these records can be freed twice during document parsing operations. The flaw exists in the document parsing engine responsible for processing structured data within Word documents, particularly when encountering malformed LFO records that trigger unexpected memory management behavior. The vulnerability is classified under CWE-415 as a double free condition, where the same memory block is deallocated twice, potentially leading to memory corruption that can be exploited by malicious actors. This issue demonstrates the complexity of memory management within office productivity applications where multiple data structures must be properly tracked and released during document processing operations.
The technical exploitation of this vulnerability occurs when a remote attacker crafts a malicious Word document containing specially constructed LFO records that cause Word's parsing engine to execute improper memory deallocation sequences. During normal document processing, Word maintains internal data structures to track formatting information for lists within documents, and these LFO records contain metadata about list formatting properties. When the crafted document is opened, the parsing logic fails to properly validate the LFO record structure, leading to a scenario where a memory pointer is freed twice before being reallocated for subsequent processing. The double free condition creates a state where the memory management heap becomes corrupted, potentially allowing an attacker to manipulate the heap layout and overwrite critical memory locations. This heap corruption can be leveraged to execute arbitrary code with the privileges of the user running Word, effectively providing a remote code execution capability. The vulnerability aligns with ATT&CK technique T1059.005 for command and script interpreter execution, as successful exploitation would enable attackers to run malicious code within the target system.
The operational impact of CVE-2010-3217 extends beyond simple remote code execution, as it represents a critical vector for lateral movement within corporate networks where Word 2002 installations exist. Organizations using legacy Word versions are particularly vulnerable since this vulnerability affects an older product line that may not receive timely security updates. The remote nature of the exploit means that attackers can deliver malicious documents via email, web downloads, or file sharing systems without requiring local access to target systems. Once exploited, the vulnerability could enable attackers to establish persistent access, escalate privileges, or deploy additional malware payloads. The vulnerability's impact is compounded by the fact that Word documents are commonly used in business environments, making the attack surface particularly broad. Organizations with limited security awareness training may inadvertently open malicious documents, triggering the exploit without user intervention. The vulnerability also demonstrates the importance of proper input validation in document processing applications, as the issue stems from inadequate validation of structured data within document formats. This flaw highlights the need for robust memory safety practices in office productivity software and emphasizes the dangers of legacy software in modern threat environments.
Mitigation strategies for CVE-2010-3217 should include immediate patching of affected Word 2002 installations with Microsoft security updates, though organizations may need to consider the compatibility implications of upgrading. Network-based protections such as email filtering and web proxy rules can help prevent the delivery of malicious documents, while endpoint protection solutions should be configured to monitor for suspicious document handling behavior. Security teams should implement strict document handling policies, including disabling automatic opening of attachments and restricting file type execution in office applications. Regular vulnerability assessments should identify all instances of Word 2002 within the organization, as these legacy systems represent significant security risks. The vulnerability also underscores the importance of maintaining current security patches and the dangers of using outdated software versions, particularly in environments where security updates are not regularly applied. Organizations should consider implementing application whitelisting to prevent execution of untrusted Word documents and establish procedures for safe document handling in collaborative environments. The remediation process must also include user education about the risks of opening unknown Word documents and the importance of keeping software up to date. Given the nature of the vulnerability, which involves memory corruption in document processing, organizations should also consider implementing memory protection mechanisms such as DEP and ASLR to make exploitation more difficult. The vulnerability serves as a reminder that even legacy applications require ongoing security attention, as they often contain undiscovered vulnerabilities that can be exploited by adversaries with sufficient knowledge and resources.