CVE-2021-40397 in WISE-PaaS
Summary
by MITRE • 01/28/2022
A privilege escalation vulnerability exists in the installation of Advantech WISE-PaaS/OTA Server 3.0.9. 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.
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Analysis
by VulDB Data Team • 02/02/2022
This privilege escalation vulnerability in Advantech WISE-PaaS/OTA Server version 3.0.9 represents a critical security flaw that allows attackers to escalate their privileges to the highest system level authority known as NT SYSTEM. The vulnerability stems from improper file handling during the installation process, creating a path for malicious actors to substitute legitimate system files with crafted malicious counterparts. The attack vector specifically targets the installation mechanism where the system fails to properly validate or secure file replacement operations, enabling unauthorized code execution with elevated privileges. This weakness directly violates security principle of least privilege and creates a pathway for complete system compromise.
The technical implementation of this vulnerability involves the manipulation of installation files that are processed with elevated privileges during the server deployment. When the system attempts to install or update components, it does not adequately verify the integrity or authenticity of the replacement files, allowing attackers to place malicious executables or scripts in critical system locations. The flaw essentially creates a race condition or validation bypass where the installation process trusts user-provided files without sufficient cryptographic verification or access control checks. This type of vulnerability falls under the CWE-276 category of insecure file permissions and improper file handling, which are common attack surfaces for privilege escalation exploits. The ATT&CK framework would classify this under T1068 - Exploitation for Privilege Escalation, specifically targeting the installation and update processes as attack vectors.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete administrative control over the affected system. With NT SYSTEM privileges, an attacker gains unrestricted access to all system resources, including the ability to modify or delete critical files, access sensitive data, install additional malicious software, and potentially establish persistence mechanisms. The vulnerability affects the entire WISE-PaaS/OTA Server ecosystem, potentially compromising multiple connected devices and systems that rely on this platform for over-the-air updates and management. Organizations using this software face significant risk of unauthorized access, data breaches, and potential lateral movement within their network infrastructure, as the compromised server could serve as a foothold for broader attacks.
Mitigation strategies for this vulnerability require immediate patching of the affected software to address the installation file handling flaws. System administrators should implement strict file integrity monitoring and access control measures to prevent unauthorized file modifications during installation processes. The principle of least privilege must be enforced through proper file permissions and access controls, ensuring that installation processes run with minimal required privileges rather than elevated system rights. Organizations should conduct comprehensive security assessments of their deployment environments to identify any systems running vulnerable versions and implement network segmentation to limit potential attack surfaces. Additionally, regular security updates and vulnerability scanning should be implemented to detect similar weaknesses in other software components and prevent exploitation of similar installation-based vulnerabilities.