CVE-2002-1716 in Office
Summary
by MITRE
The Host() function in the Microsoft spreadsheet component on Microsoft Office XP allows remote attackers to create arbitrary files using the SaveAs capability.
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Analysis
by VulDB Data Team • 06/01/2019
The vulnerability identified as CVE-2002-1716 represents a critical file system manipulation flaw within Microsoft Office XP's spreadsheet component that enables remote attackers to execute arbitrary file creation operations. This vulnerability specifically targets the Host() function implementation within the Microsoft Office XP environment, where the SaveAs capability can be exploited to create files in arbitrary locations on the target system. The flaw exists in the way the spreadsheet component handles file saving operations and lacks proper input validation and access control mechanisms. Attackers can leverage this vulnerability to place malicious files in sensitive system directories or user-accessible locations, potentially leading to privilege escalation or persistent access within the compromised environment. The vulnerability is particularly concerning as it operates at the application level within Microsoft Office XP, making it accessible to remote attackers who can trigger the malicious file creation through carefully crafted spreadsheet files or web-based attacks.
The technical exploitation of this vulnerability stems from insufficient validation of file paths and destination directories within the Host() function implementation. When the spreadsheet component processes SaveAs operations, it fails to properly sanitize or verify the target file paths, allowing attackers to specify arbitrary locations for file creation. This weakness falls under the category of improper input validation as defined by CWE-20, where untrusted data is processed without adequate sanitization. The vulnerability can be triggered through various attack vectors including maliciously crafted spreadsheet files delivered via email attachments, web downloads, or compromised websites. The lack of proper access control checks means that the component can be coerced into creating files in system directories where the user account running Microsoft Office has write permissions, potentially enabling attackers to place malware or backdoors in strategic locations. The exploitation process typically involves creating a specially formatted spreadsheet file that, when opened and saved using the SaveAs functionality, triggers the vulnerable Host() function and creates files at attacker-controlled paths.
The operational impact of CVE-2002-1716 extends beyond simple file creation capabilities, as it provides attackers with potential pathways for system compromise and persistent access. Once an attacker successfully exploits this vulnerability, they can create malicious files in system directories, potentially placing executable code or configuration files that can be executed later to maintain access. This capability aligns with ATT&CK technique T1059 for execution and T1078 for valid accounts, as the vulnerability allows for execution of arbitrary code through legitimate application interfaces. The vulnerability also enables potential privilege escalation scenarios, especially when users with elevated privileges open malicious spreadsheet files, as the created files may be placed in locations with higher system privileges. Additionally, the vulnerability can be leveraged for data exfiltration or as a stepping stone for further attacks within the network, as the created files can be used to establish persistence mechanisms or contain malicious payloads that can be executed when the target system interacts with the created files. The widespread adoption of Microsoft Office XP at the time of this vulnerability's disclosure meant that numerous systems were potentially vulnerable to this attack vector.
Mitigation strategies for CVE-2002-1716 should focus on both immediate defensive measures and long-term architectural improvements. The most effective immediate solution involves applying Microsoft security patches and updates that address the specific Host() function vulnerability within the Office XP spreadsheet component. Organizations should also implement strict file execution policies that prevent automatic execution of files from untrusted sources, particularly those with spreadsheet file extensions. Network-level protections including email filtering, web content filtering, and application whitelisting can help prevent the delivery and execution of malicious spreadsheet files that exploit this vulnerability. Security awareness training for end users becomes critical as many attacks leveraging this vulnerability rely on social engineering techniques to trick users into opening malicious files. System administrators should also implement proper file system access controls and monitor for unusual file creation patterns in system directories, as this vulnerability may be used to create files in locations where such activity is uncommon. The vulnerability highlights the importance of secure coding practices and input validation, as demonstrated by the CWE-20 classification, and organizations should review their application security practices to prevent similar issues in other components. Regular security assessments and vulnerability scanning should include checks for outdated Office versions that may be susceptible to this and similar legacy vulnerabilities.