CVE-2021-40388 in SQ Manager Server
Summary
by MITRE • 01/28/2022
A privilege escalation vulnerability exists in Advantech SQ Manager Server 1.0.6. A specially-crafted file can be replaced in the system to escalate privileges to NT SYSTEM authority. An attacker can provide a malicious file to trigger this vulnerability.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/02/2022
The vulnerability identified as CVE-2021-40388 represents a critical privilege escalation flaw within Advantech SQ Manager Server version 1.0.6, a software solution designed for industrial automation and monitoring systems. This vulnerability exposes a fundamental security weakness in the application's file handling and permission management mechanisms, creating a pathway for unauthorized users to gain elevated system privileges. The flaw specifically manifests when malicious files are introduced into the system, allowing attackers to bypass normal access controls and achieve NT SYSTEM authority, which represents the highest level of privileges available within Windows operating systems.
The technical exploitation of this vulnerability stems from improper input validation and insufficient access controls within the SQ Manager Server application. When a specially crafted file is processed by the system, the application fails to properly validate the file's integrity or verify its legitimacy before executing or installing it. This weakness creates an opportunity for attackers to substitute legitimate system files with malicious counterparts that contain code designed to elevate privileges. The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and CWE-78, which covers improper neutralization of special elements used in os command injection attacks. The attack vector specifically targets the application's file replacement functionality, where legitimate administrative processes are subverted through malicious file injection.
The operational impact of this privilege escalation vulnerability extends far beyond simple unauthorized access, as achieving NT SYSTEM authority provides complete control over the affected system. An attacker with access to this vulnerability can execute arbitrary code, modify system configurations, install malicious software, and access all data stored on the system. This level of access enables comprehensive system compromise and can lead to significant operational disruption, data breaches, and potential lateral movement within network environments. The vulnerability is particularly concerning in industrial control systems where the SQ Manager Server may be used to monitor and control critical infrastructure, as the compromise of such systems could result in operational failures, safety hazards, and regulatory compliance violations. The attack surface is further expanded by the fact that this vulnerability can be triggered through file delivery mechanisms, making it accessible to attackers who may not have direct system access.
Mitigation strategies for CVE-2021-40388 must address both immediate remediation and long-term security hardening measures. Organizations should prioritize applying vendor-provided patches or updates that address the privilege escalation vulnerability in the SQ Manager Server application. In the absence of immediate patches, network segmentation and access control measures should be implemented to limit exposure of the affected system to untrusted networks or users. The principle of least privilege should be enforced by restricting file system permissions and limiting the execution rights of the SQ Manager Server application. Additionally, security monitoring should be enhanced to detect unusual file modification patterns or unauthorized system changes that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1068, which covers exploit for privilege escalation, and T1566, which covers spearphishing with a malicious attachment. Regular security assessments and penetration testing should be conducted to verify the effectiveness of implemented controls and identify potential additional vulnerabilities in the industrial control system environment.