CVE-2017-10865 in Confidential File Decryption
Summary
by MITRE
Untrusted search path vulnerability in HIBUN Confidential File Decryption program prior to 10.50.0.5 allows an attacker to gain privileges via a Trojan horse DLL in an unspecified directory. Note this is a separate vulnerability from CVE-2017-10863.
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Analysis
by VulDB Data Team • 11/24/2019
The vulnerability identified as CVE-2017-10865 represents a critical untrusted search path weakness in the HIBUN Confidential File Decryption program version 10.50.0.5 and earlier. This flaw resides in the program's dynamic link library loading mechanism, where the application fails to properly validate the source and integrity of dynamically loaded modules. The vulnerability stems from the program's tendency to search for required DLL files in a predictable sequence of directories without sufficient verification of their authenticity or origin, creating an exploitable condition where malicious actors can place counterfeit DLL files in strategic locations.
The technical implementation of this vulnerability allows for privilege escalation through a Trojan horse attack vector. When the vulnerable decryption program executes, it follows a predetermined search order for DLL dependencies, typically starting with the current working directory, followed by system directories, and potentially user-writable locations. An attacker who can write to any directory in this search path can place a malicious DLL file with the same name as a legitimate dependency, causing the program to load and execute the attacker-controlled code with the privileges of the victim user. This behavior directly aligns with CWE-426, which describes the insecure loading of dynamic libraries, and represents a classic example of a DLL hijacking attack pattern.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential data compromise and system infiltration. Since the decryption program likely handles sensitive confidential files, successful exploitation could lead to unauthorized access to classified information, system reconnaissance, or establishment of persistent backdoors. The attack requires minimal privileges to execute, as the attacker only needs write access to one of the directories in the search path, making it particularly dangerous in environments where users have broad directory access rights. This vulnerability is particularly concerning because it operates at the operating system level, bypassing many application-level security controls and potentially allowing attackers to execute arbitrary code with elevated privileges.
Mitigation strategies for CVE-2017-10865 should focus on implementing proper DLL loading practices and system hardening measures. Organizations should immediately update to HIBUN Confidential File Decryption version 10.50.0.5 or later, which contains the necessary patches to address the untrusted search path issue. System administrators should also implement application whitelisting policies to restrict which DLL files can be loaded by the decryption program, and consider using Windows AppLocker or similar technologies to enforce strict execution policies. Additionally, the principle of least privilege should be enforced by ensuring that the decryption program runs with minimal required permissions and that user accounts have restricted write access to system directories. From an ATT&CK framework perspective, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1068 (Local Port Forwarding) techniques, as successful exploitation would likely involve command execution and potential lateral movement within the compromised system.