CVE-2017-10863 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-2017-10865.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/16/2021
The vulnerability identified as CVE-2017-10863 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 or sanitize the search path used to locate required DLL files during execution. The vulnerability creates a dangerous condition where malicious actors can place specially crafted Trojan horse DLL files in directories that the legitimate program searches before examining system directories. This behavior directly aligns with CWE-426, which describes untrusted search path vulnerabilities where applications execute code from unexpected locations due to insecure path resolution mechanisms.
The technical exploitation of this vulnerability occurs when an attacker places a malicious DLL file with the same name as a legitimate library that the HIBUN program expects to load. When the decryption program executes, it follows its configured search order and loads the attacker-controlled DLL instead of the legitimate system library. This privilege escalation opportunity arises because the program runs with elevated permissions required for decryption operations, potentially allowing the malicious code to execute with the same privileges as the legitimate application. The vulnerability specifically affects systems where the current working directory or user-writable directories appear earlier in the DLL search path than system directories, creating an attack surface where adversaries can manipulate the program's execution flow through carefully placed malicious components.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable attackers to perform privilege escalation attacks that may ultimately compromise the entire system. The HIBUN Confidential File Decryption program likely operates with high-privilege access to handle encrypted files, making successful exploitation particularly dangerous. Attackers can leverage this vulnerability to gain access to sensitive data, modify system configurations, or establish persistence mechanisms within the target environment. The vulnerability's impact is compounded by the fact that it affects a decryption tool, which typically operates with broad file system access rights and may have the ability to read and modify confidential data. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter) and T1068 (Local Privilege Escalation) techniques, as the malicious DLL execution can lead to command injection and privilege elevation within the system.
Mitigation strategies for CVE-2017-10863 should focus on addressing the root cause of the untrusted search path issue through multiple defensive layers. The most effective immediate solution involves updating the HIBUN Confidential File Decryption program to version 10.50.0.5 or later, which includes proper DLL search path validation and sanitization. Organizations should also implement the principle of least privilege by running the decryption program with minimal required permissions rather than elevated privileges. System administrators can employ security measures such as disabling unnecessary user write permissions in program directories, implementing application whitelisting policies, and using Windows Defender Application Control or similar technologies to restrict which DLLs can be loaded. Additionally, monitoring for suspicious file creation patterns in program directories and implementing strict directory access controls can help detect and prevent exploitation attempts. The vulnerability's classification as an untrusted search path issue also suggests implementing proper DLL loading practices such as using LoadLibrary with full paths or employing Safe DLL search path mechanisms to prevent malicious DLL injection attacks.