CVE-2009-2506 in Office
Summary
by MITRE
Integer overflow in the text converters in Microsoft Office Word 2002 SP3 and 2003 SP3; Works 8.5; Office Converter Pack; and WordPad in Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP2 allows remote attackers to execute arbitrary code via a DOC file with an invalid number of property names in the DocumentSummaryInformation stream, which triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 03/31/2025
This vulnerability represents a critical integer overflow flaw in Microsoft Office text conversion components that affects multiple versions of Word 2002 SP3, Word 2003 SP3, Works 8.5, the Office Converter Pack, and WordPad across Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP2. The vulnerability specifically manifests in the DocumentSummaryInformation stream processing where an invalid number of property names is encountered during DOC file parsing, creating a condition where integer arithmetic overflow occurs. This flaw falls under CWE-190, Integer Overflow or Wraparound, and more specifically aligns with CWE-129, Improper Validation of Array Index, as the system fails to properly validate the bounds of array indices during property name processing. The vulnerability operates through a heap-based buffer overflow mechanism that allows remote attackers to execute arbitrary code on affected systems.
The technical exploitation of this vulnerability occurs when a malicious DOC file contains an invalid number of property names within its DocumentSummaryInformation stream structure. During normal processing, the Office text converters attempt to parse these property names and allocate memory buffers accordingly. However, when the number of property names exceeds the maximum representable value for the integer data type used in the parsing routine, integer overflow occurs, resulting in a significantly smaller buffer allocation than required. This miscalculation creates a heap-based buffer overflow condition where subsequent data writes exceed the allocated buffer boundaries, potentially overwriting adjacent memory locations including return addresses and function pointers.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise and potential lateral movement within network environments. Attackers can leverage this vulnerability to gain unauthorized code execution privileges on vulnerable systems, potentially leading to full system compromise, data exfiltration, or establishment of persistent backdoors. The attack vector is particularly concerning as it requires no user interaction beyond opening a malicious document, making it suitable for phishing campaigns and automated exploitation. According to ATT&CK framework, this vulnerability maps to T1059.005 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as successful exploitation typically results in elevated privileges and persistent access to compromised systems.
Mitigation strategies for this vulnerability should encompass multiple layers of defense including immediate patch deployment for all affected Microsoft Office versions, implementation of email filtering solutions to block suspicious DOC attachments, and network segmentation to limit lateral movement capabilities. The primary remediation involves installing Microsoft security updates that address the integer overflow in the text conversion components, specifically targeting the DocumentSummaryInformation stream parsing routines. Additionally, organizations should implement application whitelisting policies that restrict execution of untrusted Office documents, disable unnecessary Office features that could trigger the vulnerable code paths, and conduct regular security assessments to identify potential exploitation attempts. Network-based intrusion detection systems should be configured to monitor for patterns consistent with exploitation attempts targeting this specific vulnerability, while endpoint protection solutions should be updated to detect and block malicious DOC files containing the specific malformed DocumentSummaryInformation structures that trigger the overflow condition.