CVE-2021-40396 Explained : Impact and Mitigation

This CVE-2021-40396 article provides details about a privilege escalation vulnerability in Advantech DeviceOn/iService 1.1.7, its impact, technical details, and mitigation steps.

Understanding CVE-2021-40396

CVE-2021-40396 is a high-severity vulnerability affecting Advantech DeviceOn/iService 1.1.7.

What is CVE-2021-40396?

This CVE refers to a privilege escalation flaw in the installation process of Advantech DeviceOn/iService 1.1.7. Attackers can exploit this by replacing a specially-crafted file to escalate privileges to NT SYSTEM authority.

The Impact of CVE-2021-40396

The vulnerability has a CVSS base score of 8.8, indicating a high severity level with significant impact on confidentiality, integrity, and availability.

Technical Details of CVE-2021-40396

This section covers the technical aspects of the vulnerability.

Vulnerability Description

Type: Incorrect Default Permissions (CWE-276)
Description: Allows attackers to escalate privileges by replacing a file

Affected Systems and Versions

Affected Product: Advantech DeviceOn/iService 1.1.7
Vendor: Advantech
Affected Version: 1.1.7

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Local
Privileges Required: Low
Scope: Changed
User Interaction: None

Mitigation and Prevention

Protect your systems from CVE-2021-40396 with the following steps:

Immediate Steps to Take

Monitor and restrict file replacements
Implement least privilege access
Monitor system logs for unusual activities

Long-Term Security Practices

Conduct regular security training
Keep systems and software up to date
Perform regular security audits

Patching and Updates

Apply security patches and updates from Advantech