CVE-2018-0597 in Visual Studio
Summary
by MITRE
Untrusted search path vulnerability in the installer of Visual Studio Code 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-2018-0597 represents a critical untrusted search path issue within the Visual Studio Code installer component. This flaw exists in the installation process where the installer fails to properly validate or sanitize the search paths used to locate required dynamic link libraries. The vulnerability stems from the installer's tendency to search for DLL files in multiple directories without adequate security controls, creating an opportunity for malicious actors to place specially crafted Trojan horse DLLs in strategic locations within the file system.
The technical implementation of this vulnerability aligns with CWE-427, which specifically addresses uncontrolled search path dependencies. When the Visual Studio Code installer executes, it follows a predetermined search order that includes directories such as the current working directory, system PATH locations, and potentially user-writable directories. An attacker who can influence or control the contents of these directories can place a malicious DLL with the same name as a legitimate dependency, causing the installer to load and execute the attacker-controlled code with the privileges of the user running the installer.
This vulnerability presents significant operational impact as it can be exploited to escalate privileges and execute arbitrary code on a target system. The attack vector is particularly concerning because it leverages the installer process, which typically runs with elevated privileges during installation. The attacker need only place a malicious DLL in a directory that will be searched before the legitimate DLLs, effectively performing a DLL side-loading attack. This technique allows for privilege escalation without requiring direct user interaction beyond the initial installation process.
The security implications extend beyond simple code execution to encompass potential system compromise and persistent access. When an attacker successfully exploits this vulnerability, they gain the ability to execute malicious code with the privileges of the installer process, which often includes system-level permissions. This can result in complete system compromise, data exfiltration, or the establishment of backdoors. The vulnerability is particularly dangerous in enterprise environments where Visual Studio Code installations may be performed by users with elevated privileges, and where the installer might be run with administrative rights.
Organizations should implement multiple layers of defense to mitigate this vulnerability. The primary mitigation strategy involves ensuring that the installer runs in a secure environment with restricted write permissions to directories in the search path. System administrators should consider implementing application whitelisting policies to restrict which executables can run on the system. Additionally, the principle of least privilege should be enforced, ensuring that installation processes are run with minimal required permissions rather than administrative rights. Regular security audits of system directories and monitoring for unauthorized DLL placements can help detect potential exploitation attempts. Organizations should also ensure that Visual Studio Code installations are performed from trusted sources and that all system updates are applied promptly to address known vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under T1059 for command and script interpreter and T1068 for exploit for privilege escalation, highlighting the need for comprehensive endpoint protection and monitoring solutions to detect and prevent such exploitation attempts.