CVE-2017-4918 in Horizon View
Summary
by MITRE
VMware Horizon View Client (2.x, 3.x and 4.x prior to 4.5.0) contains a command injection vulnerability in the service startup script. Successful exploitation of this issue may allow unprivileged users to escalate their privileges to root on the Mac OSX system where the client is installed.
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Analysis
by VulDB Data Team • 10/25/2019
The vulnerability identified as CVE-2017-4918 affects VMware Horizon View Client versions 2.x through 4.x prior to 4.5.0 on macOS systems. This represents a critical privilege escalation flaw that undermines the security model of the client application. The vulnerability manifests within the service startup script where improper input validation allows malicious command execution. Security researchers have classified this issue as a command injection vulnerability that directly compromises system integrity and user security posture.
The technical flaw stems from insufficient sanitization of user inputs within the service startup script execution flow. When the Horizon View Client initializes, it processes certain parameters without adequate validation or escaping mechanisms, creating an opportunity for attackers to inject arbitrary commands. This command injection occurs during the service startup phase, which is a critical point in the system lifecycle where elevated privileges are typically required. The vulnerability specifically targets the macOS environment where the client operates, making it particularly concerning for organizations that deploy VMware Horizon solutions in enterprise environments.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential full system compromise. Unprivileged users who can interact with the Horizon View Client installation can leverage this flaw to gain root access, effectively bypassing all standard user permission controls. This privilege escalation capability enables attackers to execute malicious code with system-level privileges, potentially leading to data exfiltration, system modification, or further lateral movement within the network. The vulnerability affects organizations using older versions of the Horizon View Client, creating a significant security gap in environments where patch management may be delayed or inconsistent.
Organizations should immediately implement mitigations including updating to VMware Horizon View Client version 4.5.0 or later, which contains the necessary patches to address this command injection vulnerability. System administrators should also review and restrict user access to the Horizon View Client installation directories and service startup scripts. The vulnerability aligns with CWE-77 and CWE-88 categories related to command injection and improper input validation, respectively, and maps to ATT&CK technique T1068 for local privilege escalation. Security monitoring should focus on detecting unusual command execution patterns during service startup phases, and organizations should conduct comprehensive vulnerability assessments to identify all affected systems running vulnerable versions of the client software.