CVE-2018-0592 in OneDrive
Summary
by MITRE
Untrusted search path vulnerability in Microsoft OneDrive 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 CVE-2018-0592 represents an untrusted search path issue within Microsoft OneDrive client software that creates a privilege escalation vector through Trojan horse DLL loading mechanisms. This flaw exists in the way OneDrive handles dynamic link library loading during its operation, specifically when searching for required modules in potentially compromised directories. The vulnerability is classified under CWE-427 Uncontrolled Search Path Element, which occurs when an application searches for files in directories specified by environment variables or other sources without proper validation or sanitization. Attackers can exploit this weakness by placing malicious DLL files in directories that OneDrive searches before system directories, allowing them to execute arbitrary code with elevated privileges.
The technical exploitation of this vulnerability leverages the principle of DLL hijacking, where an application loads a malicious library instead of a legitimate one due to improper search order implementation. When OneDrive attempts to load required DLLs, it searches through a series of directories including user-writable locations, and if a malicious DLL with the same name as a legitimate dependency exists in an earlier search path, the system will load the attacker-controlled module. This behavior directly aligns with ATT&CK technique T1055.001 Process Injection: Dynamic-link Library Injection, where adversaries inject malicious code into legitimate processes to evade detection and gain elevated privileges. The vulnerability affects Microsoft OneDrive versions prior to 17.3.6223.0003, where the search path implementation did not properly validate or sanitize directory paths before loading dynamic libraries.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential full system compromise and data exfiltration capabilities. An attacker with local access can leverage this vulnerability to execute malicious code with the privileges of the OneDrive service account, which often runs with elevated permissions. This creates a persistent threat vector that can be maintained across system reboots, as the malicious DLL will continue to be loaded whenever OneDrive executes. The vulnerability is particularly concerning in enterprise environments where OneDrive is widely deployed, as it could allow attackers to establish footholds in networks and potentially escalate privileges to domain administrator levels. Additionally, the attack requires minimal user interaction beyond having the OneDrive client installed, making it an attractive target for automated exploitation campaigns.
Mitigation strategies for CVE-2018-0592 should prioritize immediate software updates to the latest OneDrive versions that contain proper search path validation. Microsoft released patches in version 17.3.6223.0003 and later that address the untrusted search path issue by implementing proper DLL loading order validation and ensuring that system directories are searched before user-writable locations. Organizations should also implement application whitelisting policies that restrict which DLLs can be loaded by OneDrive, particularly in high-security environments. Network monitoring should be enhanced to detect suspicious DLL loading patterns, and system administrators should conduct regular audits of OneDrive installation directories to identify potential malicious files. The mitigation approach aligns with the principle of least privilege and defense in depth strategies recommended by cybersecurity frameworks such as NIST SP 800-171 and ISO 27001, which emphasize the importance of validating file loading operations and controlling access to system directories. Additionally, implementing Microsoft's recommended security configurations for OneDrive, including disabling unnecessary features and restricting file synchronization to trusted locations, can further reduce the attack surface.