CVE-2017-2288 in LhaForge
Summary
by MITRE
Untrusted search path vulnerability in LhaForge Ver.1.6.5 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 • 11/03/2019
The vulnerability identified as CVE-2017-2288 represents a critical untrusted search path weakness affecting LhaForge version 1.6.5 and earlier. This flaw resides in the application's dynamic link library loading mechanism, where the software fails to properly validate the source and integrity of dynamically loaded modules. The vulnerability stems from the application's insecure handling of the Windows DLL search order, which prioritizes certain directories in a predictable manner without adequate security controls. When LhaForge attempts to load required libraries, it traverses the system path in a manner that can be manipulated by an attacker to load malicious code instead of legitimate components.
This vulnerability operates under the Common Weakness Enumeration framework as CWE-426, which specifically addresses the insecure use of system search paths. The flaw enables privilege escalation through a Trojan horse attack vector where an attacker places a malicious DLL in a directory that gets searched before the legitimate library locations. The application's failure to implement proper DLL loading security measures creates an exploitable condition that can be leveraged by adversaries to execute arbitrary code with the privileges of the running process. This type of vulnerability is particularly dangerous because it can be exploited without requiring elevated privileges initially, as the application itself may run with higher privileges or in a context that allows privilege escalation.
The operational impact of this vulnerability extends beyond simple code execution, as it can facilitate complete system compromise when combined with other attack vectors. Attackers can exploit this weakness to install backdoors, steal sensitive information, or establish persistent access to affected systems. The vulnerability's exploitation requires minimal user interaction since it operates through normal application usage patterns, making it particularly stealthy and difficult to detect. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1059.001 for execution through Windows Command Shell and T1068 for privilege escalation, as it provides a mechanism for elevating privileges and maintaining access.
Mitigation strategies for CVE-2017-2288 must address the root cause of the insecure DLL loading behavior. Organizations should implement proper DLL search path security by using the LoadLibraryEx function with the LOAD_LIBRARY_AS_DATAFILE flag or by explicitly specifying full paths to required libraries. The most effective remediation involves updating to LhaForge version 1.6.6 or later, which includes proper implementation of secure library loading practices. Additional protective measures include implementing application whitelisting policies, using Windows Defender Application Control, and configuring the system to disable automatic loading of libraries from user-writable directories. System administrators should also monitor for unusual DLL loading patterns and implement least privilege principles to limit the potential impact of successful exploitation attempts.