CVE-2004-0115 in Virtual PC
Summary
by MITRE
VirtualPC_Services in Microsoft Virtual PC for Mac 6.0 through 6.1 allows local attackers to truncate and overwrite arbitrary files, and execute arbitrary code, via a symlink attack on the VPCServices_Log temporary file.
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Analysis
by VulDB Data Team • 05/17/2018
The vulnerability identified as CVE-2004-0115 resides within the VirtualPC_Services component of Microsoft Virtual PC for Mac versions 6.0 through 6.1, representing a critical security flaw that enables local attackers to manipulate system files through symbolic link attacks. This vulnerability operates at the file system level and specifically targets the VPCServices_Log temporary file, which serves as a critical logging mechanism within the virtualization environment. The flaw stems from inadequate file handling procedures that fail to properly validate or secure temporary file creation processes, creating an exploitable condition where malicious users can manipulate the system's file access patterns.
The technical implementation of this vulnerability exploits the fundamental weakness in how temporary files are created and managed within the VirtualPC_Services framework. When the service attempts to write log data to the VPCServices_Log file, it does not properly verify whether the target file path points to a legitimate location or has been intentionally replaced with a symbolic link by an attacker. This creates a race condition scenario where an attacker can establish a symbolic link pointing to a critical system file before the legitimate service attempts to write to the temporary file, thereby allowing arbitrary file truncation and overwriting operations. The flaw directly maps to CWE-377, which addresses insecure temporary file handling, and CWE-22, which covers improper limitation of a pathname to a restricted directory.
The operational impact of this vulnerability extends beyond simple file manipulation to encompass full arbitrary code execution capabilities within the context of the VirtualPC_Services process. Local attackers can leverage this weakness to overwrite system files, modify critical configuration data, or even replace executable components with malicious payloads that will execute with the privileges of the VirtualPC_Services process. The attack vector specifically targets the local threat model, meaning that any user with access to the system can potentially exploit this vulnerability, making it particularly dangerous in multi-user environments or when the virtualization software runs with elevated privileges. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, and T1078 for valid accounts, as it exploits legitimate system access to perform malicious file operations.
Mitigation strategies for this vulnerability must address both the immediate exploitation risk and the underlying design flaw in the temporary file handling mechanism. Microsoft's recommended approach involves applying the appropriate security patches that fix the file creation and validation procedures within VirtualPC_Services, ensuring that all temporary files are properly secured and that symbolic link resolution is appropriately handled. System administrators should also implement proper file system permissions and monitoring to detect unauthorized symbolic link creation. Additional protective measures include restricting user privileges for virtualization software, implementing file integrity monitoring solutions, and conducting regular security assessments of virtualization environments. The vulnerability demonstrates the importance of proper temporary file handling as outlined in the OWASP Secure Coding Practices and emphasizes the need for defensive programming techniques that prevent race conditions and improper file access patterns in system services.