CVE-2021-45809 in GlobalProtect-openconnect
Summary
by MITRE • 03/22/2022
Multiple versions of GlobalProtect-openconnect are affected by incorrect access control in GPService through DBUS, GUI Application. The way GlobalProtect-Openconnect is set up enables arbitrary users to execute commands as root by submitting the `--script=` parameter.
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Analysis
by VulDB Data Team • 03/25/2022
The vulnerability identified as CVE-2021-45809 affects multiple versions of GlobalProtect-openconnect software, specifically targeting the GPService component that operates through D-Bus communication channels. This issue represents a critical access control flaw that allows unauthorized users to escalate privileges and execute commands with root-level permissions. The vulnerability stems from improper privilege management within the GlobalProtect-Openconnect framework, creating a pathway for malicious actors to bypass intended security controls. The affected system components include both the D-Bus service layer and the graphical user interface application that interacts with the underlying GPService functionality.
The technical implementation of this vulnerability involves the improper handling of the `--script=` parameter within the GlobalProtect-Openconnect configuration. When this parameter is submitted by an unauthorized user, the system fails to validate the execution context or verify the user's authorization level before proceeding with command execution. This flaw directly relates to CWE-284, which addresses improper access control mechanisms, and CWE-78, which covers OS command injection vulnerabilities. The D-Bus interface lacks proper authentication checks and authorization validation, allowing any local user to submit malicious script parameters that are then executed with elevated privileges. The vulnerability essentially creates a privilege escalation vector where standard users can gain root access through the legitimate command execution pathways that should be restricted to authorized administrators.
The operational impact of CVE-2021-45809 extends beyond simple privilege escalation, as it fundamentally undermines the security model of the GlobalProtect-Openconnect solution. An attacker who gains access to a local user account can leverage this vulnerability to execute arbitrary commands with root privileges, potentially leading to complete system compromise. This vulnerability affects the integrity and confidentiality of the entire network infrastructure that relies on GlobalProtect for secure access control. The threat landscape for this vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and T1059, which addresses 'Command and Scripting Interpreter' execution methods. The attack surface is particularly concerning because it requires minimal privileges to exploit, making it accessible to any user who can interact with the affected system.
Mitigation strategies for CVE-2021-45809 should focus on immediate patching of affected software versions, as well as implementing additional security controls to restrict D-Bus access. Organizations should disable unnecessary D-Bus interfaces and implement proper access control lists that validate user credentials before executing privileged operations. The recommended approach includes updating to the latest GlobalProtect-Openconnect releases that contain the patched GPService implementation, enforcing strict input validation on all script parameters, and implementing monitoring for unusual command execution patterns. Security administrators should also consider implementing additional layers of protection such as mandatory access controls, privilege separation mechanisms, and comprehensive audit logging to detect and prevent exploitation attempts. The vulnerability demonstrates the critical importance of proper privilege separation and input validation in security-critical applications, particularly those that interface with system-level services through D-Bus communication protocols.