CVE-2018-0667 in SD Card Manager
Summary
by MITRE
Untrusted search path vulnerability in Installer of INplc SDK Express 3.08 and earlier and Installer of INplc SDK Pro+ 3.08 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 • 04/27/2020
The vulnerability identified as CVE-2018-0667 represents a critical untrusted search path issue affecting the installer components of INplc SDK Express 3.08 and earlier versions, as well as INplc SDK Pro+ 3.08 and earlier versions. This flaw resides within the installer's dynamic link library (dll) loading mechanism, where the system fails to properly validate the source and integrity of dynamically loaded modules during the installation process. The vulnerability manifests when the installer searches for required dll files in a predictable search path that includes user-writable directories, creating an opportunity for malicious actors to place malicious dll files in these locations. This type of vulnerability is categorized under CWE-426 Untrusted Search Path, which specifically addresses situations where applications search for libraries in directories that may be manipulated by unprivileged users.
The technical exploitation of this vulnerability occurs when an attacker places a specially crafted malicious dll file in one of the directories that the installer searches during execution. When the installer runs and attempts to load required libraries, it inadvertently loads the malicious dll instead of the legitimate one, thereby executing arbitrary code with the privileges of the installer process. This privilege escalation occurs because the installer typically runs with elevated permissions during the installation process, making the attack vector particularly dangerous. The vulnerability is classified as a privilege escalation issue under the ATT&CK framework as technique T1068, which covers the exploitation of legitimate credentials and privileges to gain elevated access. The installer's search path behavior creates a predictable attack surface where attackers can manipulate the installation process to load malicious code.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can lead to complete system compromise when attackers leverage this weakness to install backdoors, rootkits, or other persistent malware. The vulnerability affects organizations that use these specific versions of the INplc SDK, potentially exposing industrial control systems and embedded devices to unauthorized access. The attack scenario involves placing a Trojan horse dll file in a directory that the installer will traverse during execution, which could be a directory in the user's path or a directory that the installer explicitly searches. This vulnerability particularly impacts environments where the installer is run by administrators or with elevated privileges, as the malicious dll would then execute with those elevated permissions, potentially allowing attackers to establish persistent access to the system.
Mitigation strategies for CVE-2018-0667 focus on addressing the root cause through proper input validation and secure coding practices. Organizations should immediately upgrade to versions of INplc SDK that have addressed this vulnerability, as the vendor has likely implemented proper dll loading mechanisms that avoid searching untrusted directories. System administrators should implement strict access controls and file system permissions to prevent unauthorized modifications to installation directories. The principle of least privilege should be enforced, ensuring that installation processes run with minimal required permissions rather than elevated privileges. Additionally, implementing application whitelisting solutions and monitoring for suspicious dll loading activities can help detect and prevent exploitation attempts. Security professionals should also consider deploying endpoint detection and response solutions that can monitor for anomalous behavior during installation processes, particularly focusing on unexpected dll loading from non-standard directories. The vulnerability demonstrates the critical importance of secure coding practices and proper validation of dynamic library loading processes, as outlined in various secure development guidelines and industry best practices.