CVE-2017-5175 in WebAccess
Summary
by MITRE
Advantech WebAccess 8.1 and earlier contains a DLL hijacking vulnerability which may allow an attacker to run a malicious DLL file within the search path resulting in execution of arbitrary code.
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Analysis
by VulDB Data Team • 02/03/2020
The vulnerability identified as CVE-2017-5175 resides within Advantech WebAccess version 8.1 and earlier, representing a critical DLL hijacking flaw that fundamentally compromises system integrity. This vulnerability operates through the exploitation of insecure dynamic link library loading mechanisms, where the application fails to properly validate or authenticate the source of dynamically loaded libraries. The flaw allows attackers to place malicious DLL files in strategic locations within the application's search path, enabling unauthorized code execution with elevated privileges.
The technical implementation of this vulnerability stems from improper handling of dynamic library loading sequences within the Advantech WebAccess software architecture. When the application attempts to load required libraries, it searches through a predetermined set of directories without sufficient validation of the library authenticity or source. This insecure search path behavior creates an opportunity for attackers to position malicious DLLs alongside legitimate system libraries, causing the application to inadvertently execute attacker-controlled code. The vulnerability aligns with CWE-427, which specifically addresses Uncontrolled Search Path Element, and represents a classic example of how insecure library loading can lead to privilege escalation and arbitrary code execution.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a pathway to establish persistent access within industrial control systems environments where Advantech WebAccess is deployed. The attack vector typically involves placing malicious DLL files in directories that are part of the application's default search path, often including the application installation directory or system directories. This allows attackers to execute arbitrary code with the privileges of the user running the WebAccess application, potentially leading to complete system compromise and unauthorized access to critical industrial processes. The vulnerability particularly affects environments where the application runs with elevated privileges, as it can enable attackers to gain system-level control over industrial automation and control systems.
Mitigation strategies for CVE-2017-5175 should focus on implementing secure library loading practices and restricting the application's search path to minimize the risk of malicious DLL injection. Organizations should apply the vendor-provided security patches and updates immediately, as Advantech has released fixes for this vulnerability. Additional protective measures include implementing application whitelisting policies, configuring secure search paths that prioritize system directories over user directories, and monitoring for suspicious library loading activities. The ATT&CK framework categorizes this vulnerability under technique T1059.007 for Windows Command and Scripting Interpreter, as attackers may leverage the compromised system to execute additional malicious payloads through the hijacked DLL functionality. Network segmentation and privilege separation can further reduce the attack surface, while regular security assessments should verify that no malicious libraries remain in the system search paths.