CVE-2017-9661 in SCADA Software
Summary
by MITRE
An Uncontrolled Search Path Element issue was discovered in SIMPlight SCADA Software version 4.3.0.27 and prior. The uncontrolled search path element vulnerability has been identified, which may allow an attacker to place a malicious DLL file within the search path resulting in execution of arbitrary code.
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Analysis
by VulDB Data Team • 11/07/2019
The vulnerability identified as CVE-2017-9661 represents a critical uncontrolled search path element flaw within SIMPlight SCADA software version 4.3.0.27 and earlier releases. This type of vulnerability falls under the CWE-427 category, which specifically addresses uncontrolled search paths that can lead to privilege escalation and code execution. The issue stems from the software's failure to properly validate or sanitize the search paths used when loading dynamic link libraries, creating an exploitable condition where malicious actors can manipulate the execution flow.
The technical implementation of this vulnerability occurs when the SCADA software attempts to load DLL files without enforcing strict path validation mechanisms. Attackers can exploit this by placing malicious DLL files in directories that are part of the system's search path, potentially causing the software to execute unintended code when it attempts to load legitimate libraries. This flaw is particularly dangerous in industrial control environments where SCADA systems manage critical infrastructure operations, as it provides a potential entry point for adversaries seeking to compromise operational technology networks.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable attackers to gain unauthorized access to industrial control systems that manage critical processes. The attack surface is particularly concerning in environments where SCADA systems are connected to enterprise networks, as it can serve as a stepping stone for lateral movement and privilege escalation. This vulnerability directly relates to ATT&CK technique T1059.001 for command and scripting interpreter and T1546.008 for exploit for persistence, as attackers can use the malicious DLL execution to establish persistent access or escalate privileges within the targeted environment.
Organizations should implement immediate mitigations including restricting write access to directories in the search path, implementing strict DLL loading mechanisms, and conducting comprehensive security assessments of all SCADA systems. The vulnerability demonstrates the importance of applying secure coding practices, particularly in industrial control systems where the consequences of exploitation can be severe. Security teams should also consider network segmentation and monitoring for suspicious DLL loading activities. The affected SIMPlight software version should be upgraded to the latest available release that addresses this specific search path vulnerability, as the vendor has likely provided patches or updates to resolve this uncontrolled search path element issue. This vulnerability underscores the critical need for proper input validation and secure library loading practices in industrial control systems, as highlighted by various cybersecurity frameworks and standards that emphasize the protection of operational technology environments from such fundamental security flaws.