CVE-2009-0227 in PowerPoint
Summary
by MITRE
Stack-based buffer overflow in the PowerPoint 4.2 conversion filter (PP4X32.DLL) in Microsoft Office PowerPoint 2000 SP3, 2002 SP3, and 2003 SP3 allows remote attackers to execute arbitrary code via a large number of structures in sound data in a file that uses a PowerPoint 4.0 native file format, leading to memory corruption, aka "Legacy File Format Vulnerability," a different vulnerability than CVE-2009-0222, CVE-2009-0223, CVE-2009-0226, and CVE-2009-1137.
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Analysis
by VulDB Data Team • 08/11/2021
The vulnerability described in CVE-2009-0227 represents a critical stack-based buffer overflow affecting Microsoft Office PowerPoint versions 2000 SP3, 2002 SP3, and 2003 SP3 through their PowerPoint 4.2 conversion filter component known as PP4X32.DLL. This flaw specifically targets the legacy file format processing functionality that handles PowerPoint 4.0 native file formats, making it particularly dangerous for environments where older document compatibility is maintained. The vulnerability falls under the CWE-121 stack-based buffer overflow category, which is classified as a memory safety issue where data written to a stack buffer exceeds the buffer's allocated size, potentially overwriting adjacent memory locations including return addresses and control data. The attack vector involves remote exploitation through specially crafted sound data structures within PowerPoint 4.0 files, which when processed by the vulnerable conversion filter trigger memory corruption that can be leveraged for arbitrary code execution. This vulnerability operates at the application level within Microsoft Office, specifically targeting the file format conversion pipeline that bridges legacy and modern document formats.
The technical exploitation mechanism relies on the improper validation of sound data structures within PowerPoint 4.0 files that are processed through the PP4X32.DLL component. When a malicious file containing an excessive number of structures in the sound data section is opened or converted, the conversion filter fails to properly bounds-check the data being read into a fixed-size stack buffer. This allows an attacker to overflow the buffer and overwrite critical memory segments, potentially including the return address of the function executing the conversion process. The vulnerability is particularly insidious because it can be triggered through legitimate file format conversion operations, making it difficult to distinguish between benign and malicious files based solely on file extension or metadata. The attack requires the target system to process a file that utilizes the legacy PowerPoint 4.0 format, which was commonly used in older versions of the software and may still be encountered in corporate environments or archived documents. The memory corruption resulting from this overflow can lead to unpredictable program behavior, crashes, or more dangerously, complete system compromise when the attacker can control the execution flow through overwritten return addresses.
The operational impact of CVE-2009-0227 extends beyond simple code execution to encompass potential system compromise and data theft across enterprise environments where legacy Office compatibility is maintained. Attackers leveraging this vulnerability can execute malicious code with the privileges of the user running PowerPoint, potentially leading to full system compromise if the user has administrative rights. The vulnerability is particularly concerning in environments where users frequently open documents from untrusted sources or where legacy file format support is enabled by default. Organizations may experience unauthorized access to sensitive data, system availability disruption, and potential lateral movement within networks where compromised systems can serve as entry points for further attacks. The vulnerability's classification under ATT&CK technique T1203 (Exploitation for Client Execution) indicates that it can be used as a vector for initial access or privilege escalation within targeted environments. Additionally, the vulnerability's relationship to other legacy format vulnerabilities such as CVE-2009-0222, CVE-2009-0223, CVE-2009-0226, and CVE-2009-1137 demonstrates a pattern of weaknesses in Microsoft Office's handling of older file formats, highlighting the ongoing risks associated with maintaining backward compatibility for deprecated formats.
Mitigation strategies for CVE-2009-0227 should focus on both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities in file processing components. Microsoft released security updates and patches for this vulnerability that addressed the buffer overflow in the PP4X32.DLL component, and organizations should ensure all affected Office installations are updated to the latest service packs and security patches. The most effective immediate mitigation involves disabling or removing support for legacy PowerPoint 4.0 file formats from systems where they are not absolutely required, particularly in environments where users are not expected to process such documents regularly. Network administrators should implement file filtering mechanisms that prevent the automatic opening of PowerPoint 4.0 files from untrusted sources and consider using sandboxing technologies to isolate document processing activities. Organizations should also conduct comprehensive vulnerability assessments to identify any remaining systems running vulnerable versions of Office and ensure that legacy file format support is disabled in enterprise environments. The vulnerability serves as a reminder of the importance of maintaining strict input validation in file format parsers and the need for regular security updates to address known vulnerabilities in widely used productivity software components. Proper application of the principle of least privilege combined with regular patch management can significantly reduce the risk of exploitation, while network segmentation and monitoring can help detect potential exploitation attempts targeting this and similar vulnerabilities.