CVE-2018-13368 in FortiClient
Summary
by MITRE
A local privilege escalation in Fortinet FortiClient for Windows 6.0.4 and earlier allows attacker to execute unauthorized code or commands via the command injection.
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Analysis
by VulDB Data Team • 06/17/2020
This vulnerability represents a critical local privilege escalation flaw in Fortinet FortiClient for Windows versions 6.0.4 and earlier, where attackers can exploit a command injection weakness to execute unauthorized code or commands. The vulnerability stems from insufficient input validation and sanitization within the FortiClient application's command processing mechanisms, allowing malicious actors with local access to inject arbitrary commands that are subsequently executed with elevated privileges. The flaw specifically affects the Windows implementation of FortiClient, which is commonly deployed as an endpoint security solution for network access control and threat prevention.
The technical implementation of this vulnerability involves a command injection vector that occurs when the FortiClient application processes user-supplied input without proper sanitization or validation. When legitimate users or processes interact with the FortiClient service, the application fails to properly escape or filter command parameters, creating an opportunity for attackers to inject malicious commands. This weakness aligns with CWE-77 and CWE-89, which specifically address command injection vulnerabilities where untrusted data is incorporated into system commands without adequate protection mechanisms. The vulnerability typically manifests when local users can manipulate input fields or parameters that are subsequently processed by the FortiClient service, which operates with elevated privileges to perform system-level operations.
The operational impact of this vulnerability is severe as it enables attackers with local access to escalate their privileges from standard user level to system administrator level or even root privileges. Once exploited, the attacker gains complete control over the affected system, allowing them to install malware, modify system files, access sensitive data, and potentially establish persistent backdoors. This privilege escalation capability makes the vulnerability particularly dangerous in enterprise environments where FortiClient is widely deployed for network security management. The attack surface is expanded when the FortiClient service runs with elevated privileges during system operations, making it an attractive target for adversaries seeking to compromise endpoint security. The vulnerability can be exploited through various attack vectors including direct local access, social engineering techniques, or by leveraging other initial compromise methods to gain local foothold before executing the privilege escalation.
Mitigation strategies for this vulnerability should focus on immediate patching of FortiClient to versions that address the command injection flaw and implement proper input validation mechanisms. Organizations should ensure that FortiClient is updated to the latest available version that contains security fixes for this vulnerability, typically version 6.0.5 or later. Additionally, security administrators should conduct comprehensive vulnerability assessments to identify systems running affected FortiClient versions and apply remediation measures immediately. Network segmentation and privilege separation practices should be enforced to limit local user access to systems running FortiClient, while monitoring systems should be configured to detect anomalous command execution patterns. The mitigation approach aligns with ATT&CK technique T1068, which covers local privilege escalation through command injection vulnerabilities, and organizations should implement defensive measures such as application whitelisting, input validation controls, and regular security audits to prevent exploitation of similar vulnerabilities. System administrators should also consider implementing least privilege principles for FortiClient service accounts and regularly review access controls to minimize potential attack surfaces.