CVE-2017-2267 in FileCapsule Deluxe Portable
Summary
by MITRE
Untrusted search path vulnerability in FileCapsule Deluxe Portable Ver.1.0.5.1 and earlier allows an attacker to gain privileges via a Trojan horse DLL in an unspecified directory.
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Analysis
by VulDB Data Team • 10/26/2019
The vulnerability identified as CVE-2017-2267 represents a critical untrusted search path issue affecting FileCapsule Deluxe Portable version 1.0.5.1 and earlier releases. This type of vulnerability falls under the broader category of dynamic link library (dll) hijacking attacks and is classified as CWE-426 according to the Common Weakness Enumeration catalog. The flaw stems from the application's improper handling of dynamic library loading mechanisms, where the software does not properly validate or restrict the directories from which it loads executable code components.
The technical implementation of this vulnerability exploits the Windows dynamic link library loading behavior, where applications search for required dll files in a specific order of directories. When an application is configured to load dlls from a location that is not properly secured or validated, an attacker can place a malicious dll file in a directory that will be searched before the legitimate dlls, thereby causing the system to execute the attacker-controlled code instead of the intended software component. This particular vulnerability affects the FileCapsule Deluxe Portable application's ability to properly secure its search path, allowing for privilege escalation through the insertion of malicious code.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential privilege escalation and system compromise. When an attacker successfully places a Trojan horse dll in an unspecified directory that the application will search, they can effectively gain elevated privileges within the system context of the running application. This vulnerability is particularly concerning in enterprise environments where portable applications may be used by multiple users, as it could allow for persistent backdoor access or facilitate further exploitation of the compromised system. The attack vector is typically executed through social engineering or by compromising a shared directory that the application will traverse during normal operation.
Security practitioners should implement several mitigation strategies to address this vulnerability effectively. The primary remediation involves updating to the latest version of FileCapsule Deluxe Portable where the search path handling has been properly secured. Additionally, system administrators should employ the principle of least privilege by running applications with reduced permissions and implementing application whitelisting controls to prevent unauthorized dll loading. The vulnerability aligns with ATT&CK technique T1059.001 for execution through Windows command shell and T1068 for local privilege escalation, making it a significant concern for defenders monitoring for suspicious process creation and dynamic link library loading behaviors. Organizations should also conduct regular security assessments to identify other applications that may be susceptible to similar search path vulnerabilities, particularly those that do not properly validate or restrict their dll loading paths.