CVE-2022-33877 in FortiClient
Summary
by MITRE • 06/13/2023
An incorrect default permission [CWE-276] vulnerability in FortiClient (Windows) versions 7.0.0 through 7.0.6 and 6.4.0 through 6.4.8 and FortiConverter (Windows) versions 6.2.0 through 6.2.1, 7.0.0 and all versions of 6.0.0 may allow a local authenticated attacker to tamper with files in the installation folder, if FortiClient or FortiConverter is installed in an insecure folder.
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Analysis
by VulDB Data Team • 07/08/2023
The vulnerability identified as CVE-2022-33877 represents a critical permission misconfiguration flaw affecting FortiClient and FortiConverter software across multiple version ranges. This issue stems from improper default permissions assigned to installation directories, creating a path traversal and file tampering opportunity for authenticated local attackers. The vulnerability manifests when these security applications are installed in directories with insufficient access controls, allowing malicious users with legitimate login credentials to modify critical system files and potentially compromise the integrity of the protected environment.
This weakness falls under CWE-276, which specifically addresses incorrect default permissions, a category that has been consistently flagged in security assessments as a fundamental flaw in access control mechanisms. The vulnerability operates at the operating system level where the software installation process fails to establish proper discretionary access controls on the installation folders. Attackers can exploit this by leveraging their legitimate user accounts to gain unauthorized write access to the application's installation directory structure, potentially enabling privilege escalation or code injection attacks. The flaw is particularly concerning because it requires minimal attack surface - only local authentication is needed to exploit the misconfigured permissions.
The operational impact of this vulnerability extends beyond simple file tampering, as it creates potential pathways for persistent threat actors to establish footholds within enterprise networks. When FortiClient or FortiConverter applications are installed in insecure locations such as user directories or shared folders with broad permissions, the default configuration allows for unauthorized modifications to critical components including configuration files, executable binaries, or supporting libraries. This scenario directly violates the principle of least privilege and creates opportunities for attackers to modify security software itself, potentially disabling or compromising the very protection mechanisms designed to safeguard the system. The vulnerability affects organizations that deploy these applications in default installation paths without proper security hardening, particularly in environments where standard security practices are not enforced.
Mitigation strategies must address both immediate remediation and long-term security posture improvements. Organizations should immediately verify installation paths for all affected FortiClient and FortiConverter versions, ensuring that installations occur in directories with proper access controls that restrict write permissions to authorized administrative accounts only. The recommended approach involves implementing proper directory permissions using windows access control lists that limit modification rights to specific user groups and administrators. Additionally, security teams should conduct comprehensive audits of all software installations to identify similar permission misconfigurations across the enterprise. This vulnerability aligns with ATT&CK technique T1548.001 which covers abuse of sudo privileges and improper access control, and T1068 which addresses local privilege escalation through insecure software installations. Organizations should also consider implementing application whitelisting policies and regular security assessments to prevent similar issues in other software deployments. The remediation process requires careful coordination with system administrators to ensure that proper permission settings are applied without disrupting legitimate software functionality while maintaining the integrity of the security infrastructure.