CVE-2018-0598 in Windows
Summary
by MITRE
Untrusted search path vulnerability in Self-extracting archive files created by IExpress bundled with Microsoft Windows allows an attacker to gain privileges via a Trojan horse DLL in an unspecified directory.
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Analysis
by VulDB Data Team • 02/22/2020
The vulnerability identified as CVE-2018-0598 represents a critical untrusted search path issue within the IExpress component of Microsoft Windows operating systems. This flaw specifically affects self-extracting archive files generated by IExpress, which is a built-in Windows utility designed to create executable files that can extract and install components from compressed archives. The vulnerability stems from improper handling of dynamic link library (dll) loading sequences during the extraction process, creating opportunities for malicious actors to execute arbitrary code with elevated privileges.
This security weakness operates through a classic Trojan horse attack vector where an attacker places a malicious dll file in a directory that gets searched before the legitimate system directories. The vulnerability is categorized under CWE-427 Uncontrolled Search Path Element, which specifically addresses situations where applications search for files in directories that are not properly controlled or validated. When IExpress processes self-extracting archives, it follows a search path that may include user-writable directories, allowing attackers to place malicious dlls that will be loaded instead of the intended legitimate libraries. The flaw is particularly dangerous because it can be exploited to elevate privileges from standard user level to system level, as the IExpress utility typically runs with elevated permissions during the extraction process.
The operational impact of CVE-2018-0598 extends beyond simple privilege escalation to encompass broader system compromise potential. Attackers can leverage this vulnerability to execute malicious code with system-level privileges, potentially leading to complete system takeover, data exfiltration, or deployment of persistent backdoors. The vulnerability is particularly concerning because it affects Windows systems from Windows 7 through Windows 10, representing a significant attack surface across multiple generations of Microsoft operating systems. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter, as attackers can use the elevated privileges to execute commands through the compromised extraction process, and T1068 Exploitation for Privilege Escalation to gain system-level access.
Mitigation strategies for CVE-2018-0598 should focus on both immediate remediation and long-term security hardening measures. Microsoft has addressed this vulnerability through security updates that modify the IExpress behavior to properly validate and control the dll search paths. Organizations should ensure all systems are patched with the latest security updates, particularly those released in the March 2018 security bulletin. Additional protective measures include implementing strict file system permissions to limit write access to directories that might be searched during extraction processes, deploying application whitelisting solutions to prevent unauthorized dll loading, and conducting regular security audits of system directories where IExpress might be used. System administrators should also consider disabling IExpress functionality where it is not strictly required for business operations, as this eliminates the attack surface entirely. The vulnerability demonstrates the importance of proper secure coding practices and the principle of least privilege in system design, where applications should not be granted unnecessary permissions that could be exploited by attackers.