CVE-2021-23838 : Security Advisory and Response

An issue was discovered in flatCore before 2.0.0 build 139 that exposes a reflected XSS vulnerability in the media_filter HTTP request body parameter for the acp interface. This flaw allows malicious client-side scripts to be executed without proper input sanitization, enabling attackers to steal cookies and potentially launch session-hijacking attacks.

Understanding CVE-2021-23838

This section provides insights into the nature and impact of the CVE-2021-23838 vulnerability.

What is CVE-2021-23838?

CVE-2021-23838 is a reflected cross-site scripting (XSS) vulnerability in flatCore CMS that arises due to inadequate input validation of the media_filter parameter in the acp interface. This vulnerability enables threat actors to inject malicious scripts into the web application, leading to various attacks.

The Impact of CVE-2021-23838

The exploitation of CVE-2021-23838 can result in the unauthorized extraction of cookies from legitimate users' browsers. This data theft can facilitate session hijacking, allowing attackers to gain unauthorized access to the vulnerable website or web application.

Technical Details of CVE-2021-23838

Let's delve into the technical specifics of the CVE-2021-23838 vulnerability.

Vulnerability Description

The vulnerability is centered around the media_filter HTTP request body parameter in the acp interface of flatCore CMS before version 2.0.0 build 139. Due to improper input sanitization, this parameter can be manipulated to execute malicious client-side scripts.

Affected Systems and Versions

All versions of flatCore CMS prior to 2.0.0 build 139 are impacted by this vulnerability. Organizations using these versions are at risk of exploitation and data breaches.

Exploitation Mechanism

Cybercriminals can exploit the CVE-2021-23838 vulnerability by crafting a specifically designed HTTP request that contains malicious scripts in the media_filter parameter. When this payload is processed by the vulnerable application, the malicious code gets executed on the victim's browser.

Mitigation and Prevention

Discover effective strategies to mitigate and prevent the CVE-2021-23838 vulnerability.

Immediate Steps to Take

It is recommended to update flatCore CMS to version 2.0.0 build 139 or later to address the XSS vulnerability in the media_filter parameter. Additionally, input validation mechanisms should be enhanced to filter out malicious scripts.

Long-Term Security Practices

Organizations should prioritize implementing robust input validation and output encoding mechanisms to prevent XSS attacks. Security awareness training for developers and security personnel can also help in recognizing and addressing such vulnerabilities.

Patching and Updates

Regularly monitor security advisories and updates from flatCore to stay informed about the latest patches and enhancements. Promptly apply any security patches to ensure the protection of your web applications against known vulnerabilities.