CVE-2007-2588 in Excel Viewer
Summary
by MITRE
Multiple buffer overflows in the Office Viewer OCX ActiveX control (oa.ocx) 3.2 allow remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a long argument to the (1) HttpDownloadFile, (2) Open, (3) OpenWebFile, (4) DoOleCommand, (5) FTPDownloadFile, (6) FTPUploadFile, (7) HttpUploadFile, (8) Save, or (9) SaveWebFile function.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/29/2019
The vulnerability identified as CVE-2007-2588 represents a critical buffer overflow issue within the Office Viewer OCX ActiveX control version 3.2, specifically affecting the oa.ocx component. This flaw resides in the ActiveX control's handling of user-supplied input parameters, creating a significant security risk for systems that utilize this component. The vulnerability impacts multiple functions within the control, including HttpDownloadFile, Open, OpenWebFile, DoOleCommand, FTPDownloadFile, FTPUploadFile, HttpUploadFile, Save, and SaveWebFile, making it particularly dangerous as attackers can exploit any of these entry points to compromise affected systems. The vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions, and aligns with ATT&CK technique T1190 for Exploit Public-Facing Application, as the attack vector involves remote exploitation through web-based interfaces.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input parameters that exceed the allocated buffer space within the oa.ocx control. When these oversized arguments are passed to any of the vulnerable functions, the buffer overflow condition triggers, potentially leading to memory corruption that can cause the application to crash or, in more severe cases, allow arbitrary code execution. The nature of ActiveX controls makes this particularly dangerous because they are designed to run with elevated privileges, meaning successful exploitation could provide attackers with the same level of access as the user running the application. The buffer overflow affects both the stack and heap memory regions, creating opportunities for attackers to manipulate program execution flow through techniques such as return-oriented programming or direct code injection. This vulnerability demonstrates poor input validation practices within the ActiveX control, where string parameters are not properly bounded or sanitized before being processed by the underlying functions.
The operational impact of CVE-2007-2588 extends beyond simple denial of service conditions, as it represents a potential gateway for more sophisticated attacks. Systems running vulnerable versions of the Office Viewer OCX control are at risk of complete compromise, particularly in environments where users interact with untrusted web content or receive email attachments containing malicious ActiveX components. The vulnerability's remote exploitation capability means that attackers do not need physical access to the target system, making it a prime candidate for automated exploitation campaigns. Organizations that have not patched or removed vulnerable ActiveX controls remain exposed to persistent threats, as the vulnerability can be leveraged for initial access, privilege escalation, or to establish persistent backdoors within network environments. The widespread use of ActiveX controls in legacy enterprise environments increases the attack surface, particularly in corporate networks where older Office Viewer components may still be present and actively used.
Mitigation strategies for CVE-2007-2588 should focus on immediate removal or disabling of the vulnerable Office Viewer OCX control from affected systems. Microsoft recommends that organizations completely uninstall the vulnerable oa.ocx component and replace it with secure alternatives that properly validate input parameters and implement proper buffer management techniques. System administrators should implement strict ActiveX control policies through group policies or browser security settings to prevent automatic execution of potentially malicious ActiveX components. Network segmentation and application whitelisting can help reduce the attack surface by limiting which systems can execute vulnerable components. Additionally, regular security assessments should verify that no legacy ActiveX controls remain installed on systems, as these components often pose ongoing security risks even after initial vulnerabilities have been patched. Organizations should also consider implementing intrusion detection systems that can identify attempts to exploit known ActiveX vulnerabilities, as the exploitation patterns for buffer overflow conditions often generate detectable network traffic or system behavior anomalies.