CVE-2014-0818 in AutoCAD
Summary
by MITRE
Untrusted search path vulnerability in Autodesk AutoCAD before 2014 allows local users to gain privileges and execute arbitrary VBScript code via a Trojan horse FAS file in the FAS file search path.
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Analysis
by VulDB Data Team • 02/01/2022
The vulnerability identified as CVE-2014-0818 represents a critical untrusted search path issue affecting Autodesk AutoCAD versions prior to 2014. This weakness stems from the application's improper handling of file search paths during the processing of FAS files, which are AutoCAD's proprietary file format used for storing drawing data and associated resources. The vulnerability creates a dangerous condition where the software automatically searches through multiple directories to locate required files, including the current working directory and system paths, without adequate validation of the file sources.
The technical flaw manifests when AutoCAD processes a FAS file that contains malicious VBScript code within its structure. Attackers can exploit this by placing a specially crafted FAS file in a directory that AutoCAD searches automatically, effectively creating a Trojan horse scenario where legitimate software execution becomes a vector for malicious code delivery. This vulnerability falls under CWE-427 Uncontrolled Search Path, which specifically addresses the issue of applications searching in directories that can be manipulated by untrusted users. The flaw enables privilege escalation because AutoCAD typically runs with elevated permissions when processing drawing files, allowing the malicious VBScript to execute with the same privileges as the legitimate application.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a persistent method for gaining unauthorized access to systems running vulnerable AutoCAD versions. Local users can leverage this weakness to execute arbitrary code without requiring network connectivity or complex exploitation techniques, making it particularly dangerous in enterprise environments where AutoCAD is widely deployed. The vulnerability is especially concerning because FAS files are commonly shared between users and can be embedded with malicious content during normal workflow operations, creating numerous attack vectors. This issue directly maps to ATT&CK technique T1059.005 for Visual Basic and T1068 for Local Privilege Escalation, demonstrating how the vulnerability can be used to establish persistent access and escalate privileges within the target system.
Mitigation strategies for CVE-2014-0818 require immediate application of Autodesk's security patches and updates to versions 2014 and later, which address the untrusted search path behavior by implementing proper input validation and secure file handling procedures. Organizations should also implement strict file access controls and directory permissions to limit where FAS files can be placed and executed, while network segmentation can help prevent lateral movement if exploitation occurs. System administrators should consider disabling unnecessary file associations and implementing application whitelisting policies to prevent unauthorized VBScript execution. Additionally, regular security awareness training for users handling AutoCAD files can help identify potentially malicious file attachments, and continuous monitoring of system logs for unusual VBScript execution patterns should be implemented to detect potential exploitation attempts. The vulnerability underscores the importance of secure coding practices and proper input validation in preventing untrusted search path attacks that can lead to complete system compromise.