CVE-2021-21802 : Vulnerability Insights and Analysis

This CVE-2021-21802 pertains to a critical vulnerability found in the Advantech R-SeeNet web applications, specifically in the device_graph_page.php script. An attacker can exploit this flaw by crafting a malicious URL that, when accessed by a victim, can execute arbitrary JavaScript code.

Understanding CVE-2021-21802

This section delves deeper into the details of the CVE-2021-21802 vulnerability.

What is CVE-2021-21802?

CVE-2021-21802 is a critical security vulnerability in the Advantech R-SeeNet web applications. It allows an attacker to execute arbitrary JavaScript code by tricking a victim into visiting a specially crafted URL.

The Impact of CVE-2021-21802

The impact of this vulnerability is significant, with a base severity score of 9.6 (Critical) according to the CVSS v3.0 metrics. The attacker does not require any privileges to exploit this flaw, making it especially dangerous.

Technical Details of CVE-2021-21802

This section focuses on the technical aspects of CVE-2021-21802.

Vulnerability Description

The vulnerability arises from improper neutralization of input during web page generation, leading to a Cross-site Scripting (XSS) attack vector. This allows attackers to inject and execute malicious scripts in the context of the victim's browser.

Affected Systems and Versions

The affected product is Advantech R-SeeNet version 2.4.12 (released on 20th October 2020), making systems running this version vulnerable to exploitation.

Exploitation Mechanism

By manipulating input data and crafting a malicious URL, threat actors can exploit this vulnerability to execute arbitrary JavaScript code on the victim's system.

Mitigation and Prevention

Protecting against CVE-2021-21802 requires immediate action and ongoing security measures.

Immediate Steps to Take

Users are advised to update to the latest version of Advantech R-SeeNet to mitigate this vulnerability. Additionally, caution should be exercised while clicking on unverified URLs to prevent exploitation.

Long-Term Security Practices

Implementing input validation mechanisms, security headers, and regular security updates can help prevent XSS attacks and other web-based vulnerabilities.

Patching and Updates

Vendor-supplied patches and updates should be promptly applied to ensure the security of the web application and protect against potential exploitation of this vulnerability.