CVE-2012-4757 in StreamAuthor
Summary
by MITRE
Multiple untrusted search path vulnerabilities in CyberLink StreamAuthor 4.0 build 3308 allow local users to gain privileges via a Trojan horse (1) mfc71loc.dll or (2) mfc71enu.dll file in the current working directory, as demonstrated by a directory that contains a .sta or .stp file. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 02/20/2019
The vulnerability identified as CVE-2012-4757 represents a critical untrusted search path issue affecting CyberLink StreamAuthor 4.0 build 3308. This flaw resides in the application's dynamic library loading mechanism, where the software fails to properly validate the source of dynamically linked libraries. The vulnerability manifests when the application processes .sta or .stp files, which are project files used for video authoring and editing. During normal operation, StreamAuthor attempts to load Microsoft Foundation Class (MFC) libraries to provide core functionality, but it does so without implementing proper security checks to verify the authenticity and origin of these libraries.
The technical exploitation of this vulnerability occurs through a Trojan horse attack vector where malicious actors place specially crafted DLL files named mfc71loc.dll or mfc71enu.dll in the same directory as a targeted .sta or .stp file. When the vulnerable application opens these project files, it automatically loads these malicious libraries from the current working directory instead of the legitimate system locations. This behavior aligns with CWE-426, which describes untrusted search path vulnerabilities where applications search for libraries in insecure locations. The flaw essentially allows attackers to execute arbitrary code with the privileges of the user running StreamAuthor, potentially escalating from a standard user account to a higher privilege level.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a persistent means of gaining unauthorized access to systems. The vulnerability affects local users specifically, meaning that exploitation requires physical access to the target system or the ability to trick users into opening malicious project files. This makes the attack surface particularly concerning for environments where users may unknowingly open project files from untrusted sources. The attack chain typically involves placing malicious DLLs in directories where users work with video projects, then enticing them to open the associated .sta or .stp files. This approach leverages the principle of least privilege violation, where applications should not be able to load libraries from arbitrary locations without proper validation.
From a cybersecurity perspective, this vulnerability demonstrates the classic attack pattern documented in the MITRE ATT&CK framework under T1059, which covers execution through command and scripting interpreters. The vulnerability also aligns with T1546, which covers persistence mechanisms through modification of system processes. The attack vector is particularly dangerous because it exploits the trust relationship between applications and their dynamically loaded libraries, making detection difficult. The vulnerability's impact is further amplified by the fact that it affects a multimedia application that users frequently interact with, increasing the likelihood of successful exploitation.
The recommended mitigations for this vulnerability include immediate application of vendor patches if available, implementing proper privilege separation for applications handling user-provided files, and employing security measures such as Windows Defender Application Control or similar application whitelisting solutions. System administrators should also consider implementing directory permissions that prevent unauthorized DLL placement in user working directories. Additionally, users should be educated about the risks of opening project files from untrusted sources and the importance of maintaining updated software versions. The vulnerability underscores the importance of secure coding practices, specifically around library loading and search path management, which are fundamental requirements in secure software development lifecycle processes. Organizations should conduct regular vulnerability assessments to identify similar issues in other applications and implement comprehensive security controls to prevent such attacks from occurring in their environments.